6,165 research outputs found
Adipose Stromal/Stem Cell-Derived Extracellular Vesicles: Potential Next-Generation Anti-Obesity Agents
Over the last decade, several compounds have been identified for the treatment of obesity. However, due to the complexity of the disease, many pharmacological interventions have raised concerns about their efficacy and safety. Therefore, it is important to discover new factors involved in the induction/progression of obesity. Adipose stromal/stem cells (ASCs), which are mostly isolated from subcutaneous adipose tissue, are the primary cells contributing to the expansion of fat mass. Like other cells, ASCs release nanoparticles known as extracellular vesicles (EVs), which are being actively studied for their potential applications in a variety of diseases. Here, we focused on the importance of the con-tribution of ASC-derived EVs in the regulation of metabolic processes. In addition, we outlined the advantages/disadvantages of the use of EVs as potential next-generation anti-obesity agents
The role of urban boundary layer investigated with high-resolution models and ground-based observations in Rome area: a step towards understanding parameterization potentialities
Abstract. The urban forcing on thermodynamical conditions can greatly influence the local evolution of the atmospheric boundary layer. Heat stored in an urban environment can produce noteworthy mesoscale perturbations of the lower atmosphere. The new generation of high-resolution numerical weather prediction models (NWP) is nowadays often applied also to urban areas. An accurate representation of cities is key role because of the cities' influence on wind, temperature and water vapor content of the planetary boundary layer (PBL). The Advanced Weather Research and Forecasting model WRF (ARW) has been used to reproduce the circulation in the urban area of Rome. A sensitivity study is performed using different PBL and surface schemes. The significant role of the surface forcing in the PBL evolution has been investigated by comparing model results with observations coming from many instruments (lidar, sodar, sonic anemometer and surface stations). The impact of different urban canopy models (UCMs) on the forecast has also been investigated. One meteorological event will be presented, chosen as statistically relevant for the area of interest. The WRF-ARW model shows a tendency to overestimate the vertical transport of horizontal momentum from upper levels to low atmosphere if strong large-scale forcing occurs. This overestimation is partially corrected by a local PBL scheme coupled with an advanced UCM. Moreover, a general underestimation of vertical motions has been verified
Autosomal-dominant myopia associated to a novel P4HA2 missense variant and defective collagen hydroxylation
We recently described a complex multisystem syndrome in which mild-moderate myopia segregated as an independent trait. A plethora of genes has been related to sporadic and familial myopia. More recently, in Chinese patients severe myopia (MYP25, OMIM:617238) has been linked to mutations in P4HA2 gene. Seven family members complaining of reduced distance vision especially at dusk underwent complete ophthalmological examination. Whole-exome sequencing was performed to identify the gene responsible for myopia in the pedigree. Moderate myopia was diagnosed in the family which was associated to the novel missense variant c.1147A > G p.(Lys383Glu) in the prolyl 4-hydroxylase,alpha-polypeptide 2 (P4HA2) gene, which catalyzes the formation of 4-hydroxyproline residues in the collagen strands. In vitro studies demonstrated P4HA2 mRNA and protein reduced expression level as well as decreased collagen hydroxylation and deposition in mutated fibroblast primary cultures compared to healthy cell lines. This study suggests that P4HA2 mutations may lead to myopic axial elongation of eyeball as a consequence of quantitative and structural alterations of collagen. This is the first confirmatory study which associates a novel dominant missense variant in P4HA2 with myopia in Caucasian patients. Further studies in larger cohorts are advisable to fully clarify genotype-phenotype correlations.We recently described a complex multisystem syndrome in which mild-moderate myopia segregated as an independent trait. A plethora of genes has been related to sporadic and familial myopia. More recently, in Chinese patients severe myopia (MYP25, OMIM:617238) has been linked to mutations in P4HA2 gene. Seven family members complaining of reduced distance vision especially at dusk underwent complete ophthalmological examination. Whole-exome sequencing was performed to identify the gene responsible for myopia in the pedigree. Moderate myopia was diagnosed in the family which was associated to the novel missense variant c.1147A > G p.(Lys383Glu) in the prolyl 4-hydroxylase,alpha-polypeptide 2 (P4HA2) gene, which catalyzes the formation of 4-hydroxyproline residues in the collagen strands. In vitro studies demonstrated P4HA2 mRNA and protein reduced expression level as well as decreased collagen hydroxylation and deposition in mutated fibroblast primary cultures compared to healthy cell lines. This study suggests that P4HA2 mutations may lead to myopic axial elongation of eyeball as a consequence of quantitative and structural alterations of collagen. This is the first confirmatory study which associates a novel dominant missense variant in P4HA2 with myopia in Caucasian patients. Further studies in larger cohorts are advisable to fully clarify genotype-phenotype correlations
A yeast synthetic network for in-vivo assessment of reverse engineering and modelling.
Systems biology approaches are extensively used to model and reverse engineer gene regulatory networks from experimental data. Conversely, synthetic biology allows ‘‘de novo’’ construction of a regulatory network to seed new functions in the cell. At present, the usefulness and predictive ability of modeling and reverse engineering cannot be assessed and compared rigorously. We built in the yeast Saccharomyces cerevisiae a synthetic network, IRMA, for in vivo ‘‘benchmarking’’ of reverse-engineering and modeling approaches. The network is composed of five genes regulating each other through a variety of regulatory interactions; it is negligibly affected by endogenous genes, and it is responsive to small molecules. We measured time series and steady-state expression data after multiple perturbations. These data were used to assess state-of-the-art modeling and reverse-engi- neering techniques. A semiquantitative model was able to capture and predict the behavior of the network. Reverse engineering based on differential equations and Bayesian networks correctly inferred regulatory interactions from the experimental data
Investigating the Role of Guanosine on Human Neuroblastoma Cell Differentiation and the Underlying Molecular Mechanisms
Neuroblastoma arises from neural crest cell precursors failing to complete the process of differentiation. Thus, agents helping tumor cells to differentiate into normal cells can represent a valid therapeutic strategy. Here, we evaluated whether guanosine (GUO), a natural purine nucleoside, which is able to induce differentiation of many cell types, may cause the differentiation of human neuroblastoma SH-SY5Y cells and the molecular mechanisms involved. We found that GUO, added to the cell culture medium, promoted neuron-like cell differentiation in a time- and concentration-dependent manner. This effect was mainly due to an extracellular GUO action since nucleoside transporter inhibitors reduced but not abolished it. Importantly, GUO-mediated neuron-like cell differentiation was independent of adenosine receptor activation as it was not altered by the blockade of these receptors. Noteworthy, the neuritogenic activity of GUO was not affected by blocking the phosphoinositide 3-kinase pathway, while it was reduced by inhibitors of protein kinase C or soluble guanylate cyclase. Furthermore, the inhibitor of the enzyme heme oxygenase-1 but not that of nitric oxide synthase reduced GUO-induced neurite outgrowth. Interestingly, we found that GUO was largely metabolized into guanine by the purine nucleoside phosphorylase (PNP) enzyme released from cells. Taken together, our results suggest that GUO, promoting neuroblastoma cell differentiation, may represent a potential therapeutic agent; however, due to its spontaneous extracellular metabolism, the role played by the GUO-PNP-guanine system needs to be further investigated
Breast cancer-secreted miR-939 downregulates VE-cadherin and destroys the barrier function of endothelial monolayers.
Abstract Exosomes-secreted microRNAs play an important role in metastatic spread. During this process breast cancer cells acquire the ability to transmigrate through blood vessels by inducing changes in the endothelial barrier. We focused on miR-939 that is predicted to target VE-cadherin, a component of adherens junction involved in vessel permeability. By in silico analysis miR-939 was found highly expressed in the basal-like tumor subtypes and in our cohort of 63 triple-negative breast cancers (TNBCs) its expression significantly interacted with lymph node status in predicting disease-free survival probability. We demonstrated, in vitro , that miR-939 directly targets VE-cadherin leading to an increase in HUVECs monolayer permeability. MDA-MB-231 cells transfected with a miR-939 mimic, released miR-939 in exosomes that, once internalized in endothelial cells, favored trans-endothelial migration of MDA-MB-231-GFP cells by the disruption of the endothelial barrier. Notably, when up taken in endothelial cells exosomes caused VE-cadherin down-regulation specifically through miR-939 as we demonstrated by inhibiting miR-939 expression in exosomes-releasing TNBC cells. Together, our data indentify an extracellular pro-tumorigenic role for tumor-derived, exosome-associated miR-939 that can explain its association with worse prognosis in TNBCs
Guanosine-mediated anxiolytic-like effect: Interplay with adenosine a1 and a2a receptors
Acute or chronic administration of guanosine (GUO) induces anxiolytic-like effects, for which the adenosine (ADO) system involvement has been postulated yet without a direct experimental evidence. Thus, we aimed to investigate whether adenosine receptors (ARs) are involved in the GUO-mediated anxiolytic-like effect, evaluated by three anxiety-related paradigms in rats. First, we confirmed that acute treatment with GUO exerts an anxiolytic-like effect. Subsequently, we investigated the effects of pretreatment with ADO or A1R (CPA, CCPA) or A2AR (CGS21680) agonists 10 min prior to GUO on a GUO-induced anxiolytic-like effect. All the combined treatments blocked the GUO anxiolytic-like effect, whereas when administered alone, each compound was ineffective as compared to the control group. Interestingly, the pretreatment with nonselective antagonist caffeine or selective A1R (DPCPX) or A2AR (ZM241385) antagonists did not modify the GUO-induced anxiolytic-like effect. Finally, binding assay performed in hippocampal membranes showed that [3H]GUO binding became saturable at 100–300 nM, suggesting the existence of a putative GUO binding site. In competition experiments, ADO showed a potency order similar to GUO in displacing [3H]GUO binding, whereas AR selective agonists, CPA and CGS21680, partially displaced [3H]GUO binding, but the sum of the two effects was able to displace [3H]GUO binding to the same extent of ADO alone. Overall, our results strengthen previous data supporting GUO-mediated anxiolytic-like effects, add new evidence that these effects are blocked by A1R and A2AR agonists and pave, although they do not elucidate the mechanism of GUO and ADO receptor interaction, for a better characterization of GUO binding sites in ARs
Exploring manufacturing process and degradation products of gilt and painted leather
In this work, we studied the manufacturing processes and the conservation state of gilt and painted leather fragments from Palazzo Chigi in Ariccia (Italy) by using different analytical techniques. Leather fragments present a silver leaf superimposed onto leather support. A gold varnish and different painted layers decorate it all. A top-down analytical approach was used to investigate this complex multilayer structure, which adopted techniques with different sampling depths. Organic and inorganic constitutive materials together with related degradation products were studied by time of flight secondary ion mass spectrometry (ToF-SIMS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and macro X-ray fluorescence (MA-XRF). The findings have revealed the presence of different elements and species as calcium and iron in the leather support, which was attributed to the un-hairing process in the leather tanning. Regarding what concerns the silver leaf, where the varnish cracked, silver chlorides, oxides, and sulfides were detected as degradation products of the silver leaf. Proteinaceous compounds were also identified where the silver leaf is unprotected by the varnish. These ion signals reveal a potential use of animal glue on both sides of the silver leaf to promote durable adhesion. In the gold varnish, the surface analysis revealed organic compounds such as resins and oils. In particular, the copresence of linoleic, arachidonic, and lignoceric acid ion signals in the yellow area suggests the use of aloe as a colorant. Lead ions in the same area were detected and attributed to the use of lead as siccative. Blue areas were obtained by using indigo and lead white in addition to an oil binder. This is confirmed by the detection of indigotin, fatty acid, and lead soap ion signals. A copper-based pigment was used to depict the green areas and copper oxalates were identified as its degradation products. Lastly, no significant information about the red colorant was obtained. Colophony is present as a component of the final varnish
Retrieval of foreign-broadened water vapor continuum coefficients from emitted spectral radiance in the H2O rotational band from 240 to 590 cm −1
The paper presents a novel methodology to retrieve the foreign-broadened water vapor continuum absorption coefficients in the
spectral range 240 to 590 cm−1 and is the first estimation of the continuum coefficient at wave numbers smaller than 400 cm−1 under atmospheric conditions. The derivation has been accomplished by processing a suitable
set of atmospheric emitted spectral radiance observations obtained during the March 2007 Alps campaign of the ECOWAR project (Earth COoling by WAter vapor Radiation). It is shown that, in the range 450 to 600 cm−1, our findings are in good agreement with the widely used Mlawer, Tobin-Clough, Kneizys-Davies (MT_CKD) continuum. Below 450 cm−1 however the MT_CKD model overestimates the magnitude of the continuum coefficient.Published15816-158331.8. Osservazioni di geofisica ambientaleJCR Journalreserve
High SMAD7 and p-SMAD2,3 expression is associated with environmental enteropathy in children
This work was supported by grants from the Bill & Melinda Gates Foundation (SAA: OPP1066200, PK: OPP1066118, GM: OPP1131242)
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