273 research outputs found
Dataset on biomimetic hierarchically arranged nanofibrous structures resembling the architecture and the passive mechanical properties of skeletal muscles: a step forward towards artificial muscles
No full textThe present database contains the data presented and discussed in the paper “Biomimetic hierarchically arranged nanofibrous structures resembling the architecture and the passive mechanical properties of skeletal muscles: a step forward towards artificial muscle” by Carlo Gotti, Alberto Sensini, Gianmaria Fornaia, Chiara Gualandi, Andrea Zucchelli and Maria Letizia Focarete, accepted for publication in the journal Frontiers in Bioengineering and Biotechnology (2020, doi 10.3389/fbioe.2020.00767). The paper describes an approach for the biomimetic design of engineered muscle, that makes use of an elastomeric polyurethane with suitable mechanical performances, processed with the electrospinning technology, to produce a hierarchically arranged nanofibrous structure resembling the architecture and passive biomechanical properties of skeletal muscles. Scaffolds morphology and physical properties are studied and a detailed analysis of material mechanical properties is performed, taking into account the different levels of increasing complexity, going from mats to bundles and finally the hierarchical nanofibrous electrospun structure (HNES). Data include the thermal characterization of the pristine PU pellets (thermogravimetric and differential scanning calorimetry analysis), force-displacement data obtained through mechanical tensile tests along with the different geometrical and physical characterization of the samples, the results of the mechanical characterization, data on the nanofibrous alignment and the outcome of a statistical analysis
Lo sviluppo della mentalizzazione in età evolutiva. La relazione tra attaccamento e fiducia epistemica
No full textLa mentalizzazione si riferisce alla capacità umana di comprendere il comportamento proprio e altrui intrepretando intenzioni, desideri e motivazioni sottostanti. Tale competenza si sviluppa nel contesto delle relazioni di attaccamento ed è funzionale a garantire il benessere psicologico trasversalmente ad ogni fase del ciclo di vita. Una buona mentalizzazione è garantita dalla fiducia epistemica legata all’apprendimento sociale e all’esplorazione della propria e altrui mente. Il presente studio vuole approfondire il legame tra mentalizzazione, fiducia epistemica e attaccamento sicuro in età evolutiva attraverso compiti di narrazioni autobiografiche e di storytelling interpersonale in un campione di bambini non clinici
Therapeutic targeting of cellular prion protein: toward the development of dual mechanism anti-prion compounds
No full textPrP Sc , a misfolded, aggregation-prone isoform of the cellular prion protein (PrP C ), is the infectious prion agent responsible for fatal neurodegenerative diseases of humans and other mammals. PrP Sc can adopt different pathogenic conformations (prion strains), which can be resistant to potential drugs, or acquire drug resistance, posing challenges for the development of effective therapies. Since PrP C is the obligate precursor of any prion strain and serves as the mediator of prion neurotoxicity, it represents an attractive therapeutic target for prion diseases. In this minireview, we briefly outline the approaches to target PrP C and discuss our recent identification of Zn(II)-BnPyP, a PrP C -targeting porphyrin with an unprecedented bimodal mechanism of action. We argue that in-depth understanding of the molecular mechanism by which Zn(II)-BnPyP targets PrP C may lead toward the development of a new class of dual mechanism anti-prion compounds
SUBSTRATE OF POLYMERIC MATERIAL AND METHOD OF CARRYING OUT THEREOF
No full textThe main object of the present invention is to propose a substrate for wound care that is economically cheap and that can be stored also at room temperature in ambient atmosphere conditions.
Another aim of the invention is to propose a substrate that can be applied to patients in non-sterile room and that doesn't need a broad-spectrum antibiotic treatment.
A further aim is to propose a substrate useful for the preparation of a medicament that can be applied directly on the damaged tissue, such medicament having better therapeutic and wound healing properties with respect to presently existing commercial products. The polymeric material substrate is an artificial support constituted by continuous polymer fibres, preferably characterized by a diameter value lower than 1 .micro. .tau. .
Such a substrate contains antimicrobial and/or helping tissue regeneration substances, selected among Hyperforin, Adhyperforin, I-3 Diapigenin, II-8 Diapigenin, Rutin, Quercetin, Hypericin, Azadirachtin .alpha.-.beta., Nimbin, Nimbidin, Salanin, Gallic Acid, Gedunin and their blends
THE PHD FINGER OF SP140: A STRUCTURAL AND FUNCTIONAL STUDY
No full textSp140 is an IFNg-inducible leukocyte-specific member of the Sp100 family proteins. Along with the PML tumor suppressor, Sp100 family proteins are major components of PML-nuclear bodies (PML-NBs), they interact with DNA and various regulatory factors and may be involved in chromatin-dependent transcriptional activation or repression. Sp140 is expressed in all human mature B cells and plasma cell lines, as well as some T cells, suggesting an important role in cellular functions that are peculiar to these cells. In mammalian cells Sp140 behaves as a transcription co-activator for a reporter gene (Bloch et al, 2000). Despite the involvement in B-cell Chronic Lymphocytic Leukaemia (CLL, OMIM151400) (Di Bernardo et al, 2008) and HIV-1 replication (Guldner et al, 1992), until now Sp140 physiological and pathological role is unknown and unexplored, both at cellular and molecular level.
The predicted Sp140 amino acid sequence, 867 residues in length, indicates a modular structure similar to other Sp100 family members (Bloch et al, 1996). The N-terminus HSR domain (amino acids 36-157) is responsible both for PML-NBs targeting and homo/hetero-dimerization. The region between residues 306-404 is strongly negatively charged, while the central portion contains a putative bipartite nuclear localization signal, a SAND domain (residues 588-661), a PHD finger (residues 692-734) and a bromodomain (residues 756-859). In this thesis we investigated Sp140 PHD finger both at functional and structural level.
Structural determination was performed in solution by means of NMR spectroscopy. Analysis of 1H-15N HSQC spectra of Sp140 15N PHD finger wild type and 15N PHD finger P45A mutant revealed peptidyl-prolyl cis trans isomerization of the T44-P45 peptide bond and a ratio between cis and trans conformers of 1:2. As the NetPhos 2.0 server predicts phosphorylation of the T44 residue by the p38 mitogen-activated protein kinase (p38 MAPK), we suppose that the phosphorylated T44-P45 bond might be a site of regulation of the domain structure through the activity of PIN-1, an enzyme that efficiently and specifically bind to and isomerizes the phosphorylated S/T-P motifs in proteins (Wulf et al, 2005).
Using triple resonance NMR experiments we assigned 95% of backbone resonances, 96% of side chain 1H resonances and 73% of side chain non-1H resonances (side chain resonances of OH, SH, CO, NH and NH2 groups were not assigned) of the Sp140 PHD finger trans conformer. The tautomeric state of the two histidines was determined, analyzing a 1H-15N long range correlation HSQC spectrum. The 3J(HNHa) coupling constants and the corresponding phi dihedral angles were calculated by analysis of the 3D HNHA spectrum and were then compared to those predicted by TALOS+ software. We manually assigned more than 850 NOE cross-peaks of the 2D and 3D NOESY spectra. NOEs restraints and 12 dihedral angles were employed for structure calculation of the Sp140 trans conformer by means of ARIA 2.1.3 software. The best NMR ensemble achieved up to now showed a compact globular fold with two short a-helices (stretches 12-EVCR-15 and 50-FCRM-53) as the sole elements of secondary structure. Analysis of the electrostatic surface potential revealed the strong negative charged character of the Sp140 PHD finger trans conformer, with a positive patch only on one side of the domain.
Heteronuclear NOE experiments revealed that loop 2, containing the T44-P45 bond which undergoes cis trans isomerization is flexible from E40 to N47. Also the N-terminal tail of the domain is flexible up to residue L8. Flexibility caused a limited number of available NOE restraints in these two regions, especially in loop 2, and consequently an overall high backbone RMSD of the NMR ensemble. In order to increase the number of NOE restraints to calculate the structure we have recently acquired NOESY spectra at higher magnetic fields (900 MHz 1H frequency) that will be soon analyzed.
We next investigated the functional role of Sp140 PHD finger and verified its ability to work as histone binding modules. According to sequence alignments, Sp140 PHD finger belongs to the PHD finger subclass specifically recognizing the H3K4me0 epigenetic mark. Indeed, it has an N-terminal conserved aspartic acid which should be involved in electrostatic interactions with the unmodified histone K4 side-chain, as previously demonstrated by both AIRE PHD1 (Chignola et al, 2009) and BHC80 PHD finger (Lan et al, 2007) structures in complex with an unmodified H3 peptide. Unexpectedly tryptophan fluorescence and NMR titrations of Sp140 PHD finger with a 15mer H3K4me0 peptide showed no binding, indicating that the presence of the N-terminal acidic hallmark is not sufficient to predict binding to the H3K4me0 epigenetic mark. We next explored the possibility that SP140 PHD finger might recognize other epigenetic modifications, we therefore extended our binding assays to other synthetic peptides carrying different types of epigenetic marks (such as methylation or acetylation). We also applied a large screening approach using the MODifiedTM Histone Peptide Arrays, which allows the screening of 384 unique modification combinations on the N-terminal tails of histone H3 (up to residue 45), H4 (up to residue 30), H2A and H2B (up to residue 19). However, until now we identified no specific binding of Sp140 PHD finger to the unmodified histone tails and to any combination of histone epigenetic marks spotted on the array (acetylation, methylation, phosphorylation and citrullination).
Taken together these data suggest that Sp140 PHD finger is not a classical epigenetic reader and other functions might be attributed to this domain, such as a SUMO E3 ligase activity towards the adjacent bromodomain. This hypothesis was supported by the presence of a typical KxE SUMOylation site at the N-terminus of the Sp140 bromodomain (761-LKCE-764) and by recent data on KAP1 PHD finger, which functions as SUMO E3 ligase for the adjacent bromodomain (Ivanov et al, 2007; Zeng et al, 2008). In support to this hypothesis NMR titration experiments revealed binding of recombinant SUMO E2 ligase Ubc9 to a small, well defined surface of Sp140 PHD finger. We next expressed and purified in E.coli Sp140 PHD finger – bromodomain (PB) tandem and through in vitro SUMOylation test and mass spectrometry analysis we found that the construct was SUMOylated on lysine K837. This residue constitutes an atypical SUMOylation site, located at the bromodomain BC loop. Importantly, sequence alignment reveals that this position corresponds to one of the four SUMOylation sites indentified in KAP1 bromodomain. The intramolecular SUMO E3 ligase activity of Sp140 PHD finger is also supported by the observation that Sp140 PHD finger and bromodomain interact with each other, as deduced by superposition of the 1H-15N HSQC spectra of Sp140 PHD finger alone and PB tandem. Interaction could occur through the hydrophobic core made by stretch 765-FLLLKV-770 in the bromodomain and V695, F712, F718, F732 residues in the PHD finger. Indeed, this is the same core that mediates KAP1 PHD finger and bromodomain interaction, leading to a structural and functional unit whose integrity is fundamental for the KAP1 PHD finger SUMO E3 liagse activity (Zeng et al, 2008). Through NMR titrations we also demonstrated binding of SUMO-1 to both Sp140 PHD finger alone and PB tandem. The binding surface mapped on the homology model of the PB tandem is in agreement with the covalent addition of one SUMO-1 moiety to both the bromodomain K873 and K762 (in the typical KxE SUMOylation site at the bromodomain N-terminus). We are currently performing mutagenesis experiments to confirm the two Sp140 PB tandem SUMOylation sites by means of in vitro SUMOylation tests and mass spectrometry analysis on the Sp140 PB tandem single mutants K762R and K837R. To further validate the intramolecular SUMO E3 ligase activity of the PHD finger we will perform in vitro SUMOylation tests on a PB tandem mutant, in which the function of the PHD finger is inhibited trough an unfolding mutation.
In this thesis we have collected strong evidences that in vitro Sp140 PHD finger has SUMO E3 ligase activity for the adjacent bromodomain. This finding might have an important biological relevance in the context of the full length protein: first of all the SUMO E3 ligase activity correlates well with Sp140 localization in leukocytes PML-NBs. PML-NBs are nuclear sub-compartments in which 48% of their protein components show one or more SUMOylation sites which, once they are SUMOylated, work as PML-NBs recruitment signal for these proteins (Van Damme et al, 2010). A similar mechanism could be hypothesized for Sp140 protein, whereby the PHD finger mediates the SUMOylation of the adjacent bromodomain in order to enable the protein recruitment to PML-NBs. SUMOylation might also have a role in the Sp140 transcription co-activating function, other than localization. It is conceivable that Sp140 SUMOylation might recruit proteins able to interact non-covalently with the conjugated SUMO-1 through their SIMs (SUMO Interaction Motifs). Hereby SUMOylated Sp140 protein might serve as a platform for the assembly of a leukocyte-specific transcription complex, whose target genes are still to be identified. Importantly, a similar mechanism has been observed for the co-repressor KAP1; SUMOylation is required for KAP1-mediated gene silencing, because the SUMOylated bromodomain serves as a scaffold and recruits the SETDB1 histone methyltransferase and the CHD3/Mi2 component of the NuRD complex through recognition of the SUMO moieties by the SIMs of these proteins (Ivanov et al, 2007).
Through NMR and ITC titrations we found that Sp140 PB tandem is able to bind to a 15mer H3K9ac synthetic peptide. We excluded any PHD finger involvement in this interaction, because when we titrated the H3K9ac peptide to Sp140 PHD finger alone we did not see any binding. Therefore Sp140 bromodomain seems to retain the characteristic ability of bromodomains to bind to acetylated histone tails, despite it does not show the conserved Tyr, Tyr and Asn residues employed by bromodomains in order to bind to acetylated lysines. If confirmed, these results suggest that Sp140 bromodomain is characterized by a new, peculiar mode of recognition of acetylated histone tails.
In conclusion, we are collecting important functional and structural data on two domains (PHD finger and bromodomain) of Sp140, a leukocyte-specific nuclear protein involved in B-cell Chronic Lymphocytic Leukaemia and HIV-1 replication, but unexplored up to now. Our functional data strongly indicate that the two domains interact with each other constituting a structural and functional unit in which the PHD finger mediates SUMOylation of the bromodomain. We are solving the NMR solution structure of the Sp140 PHD finger trans conformer. With the exception of the T44-P45 peptidyl-prolyl cis trans isomerization, we are not observing great differences with the solved structures of PHD fingers recognizing histone H3 epigenetic marks, on the contrary of Sp140 PHD finger. Therefore, our data further support the concept that PHD fingers are versatile domains able to perform different activities according subtle but significant structural differences
L’interpretazione contemporanea di un isolato della Roma barocca. Riprogettazione e rappresentazione tridimensionale delle fasi di trasformazione dell’isolato compreso tra via Crispi, via Sistina, via del Tritone e via Zucchelli.
No full textIl Laboratorio di progettazione del Master in Restauro architettonico e cultura del patrimonio ha studiato nel corso delle edizioni XII e XIII (2014-2015) il restauro urbano dell’isolato del centro storico di Roma delimitato dalle vie Crispi, Sistina, del Tritone e Zucchelli.
L’isolato, posto al limite della zona densamente urbanizzata fin dall’epoca romana, ha subito numerose modifiche e trasformazioni, soprattutto nella seconda metà del XIX secolo. La zona centraleera occupata sin dalla fine del XVI secolo dal Convento delle Carmelitane Scalze e sue pertinenze.
Mentre il fronte su via Crispi, oggi occupato dalla Galleria Comunale di Arte Moderna e Contemporanea, e l’adiacente chiesa di San Giuseppe si sono conservate nel tempo, la parte del complesso conventuale che si estendeva sulla parallela via Zucchelli ha subito una serie di consistenti demolizioni nel 1935 a causa di dissesti delle strutture murarie. Da allora l’area, destinata a deposito della nettezza urbana, si trova in uno stato di deprecabile degrado. Il laboratorio di progettazione del Master ha offerto all’amministrazione capitolina gli studi e i progetti dei suoi studenti, come già avvenuto in alcune precedenti edizioni, per risarcire un vuoto urbano degno di miglior futuro.
Lo scopo del progetto di restauro, insieme architettonico ed urbano, è il ripristino dei volumi perduti delle case su via Zucchelli e del Convento di San Giovanni a Capo le case in funzione della ricomposizione dell’isolato e tenendo conto della necessaria convivenza tra l’assetto premoderno e i nuovi edifici realizzati dopo il 1870. L’assetto dell’area interna è stato studiato alla luce dei necessari collegamenti tra i nuovi spazi ampliati della Galleria comunale, i resti archeologici rinvenuti nel corso dei recenti scavi della Soprintendenza statale, e l’edificio della Galleria Gagosian.
Un risultato non secondario è stato quello di restituire, sulla base di una consistente documentazione iconografica, la rappresentazione tridimensionale delle fasi evolutive di una pezzo di città di grande interesse storico e architettonico
Nanovascularization of Polymer Matrix: Generation of Nanochannels and Nanotubes by Sacrificial Electrospun fibers
No full textSeveral methods for creating vascular structures, made of either discrete or interconnected channels have been developed. The currently employed methods enable the formation of channels with diameters in the millimetric and micrometric scale. However, the formation of an interconnected three-dimensional (3D) vasculature by using a rapid and scalable process is a challenge and largely limits the fields of applicability of these innovative materials. Here, we propose the use of electrospun nonwoven mats as sacrificial fibers to easily generate 3D macroscale vascularized composites containing interconnected networks with channels and tubes having submicrometric and nanometric diameters. The novel approach has the potentialities to give rise to a novel generation of composites potentially displaying new and enhanced functionalities thanks to the nanoscale features of the cavities
The geek and the chemist: Antioxidant capacity measurements by DPPH assay in beverages using open source tools, consumer electronics and 3D printing
No full textMicrocontrollers and single-board computers are widespread tools for innovative educational labs, for prototyping and for accomplish everyday tasks by expert users. Moreover, these modules are opening new exciting possibilities in the area of biological and chemical assays. In this study a Raspberry Pi computer assembled with 3D printed parts and inexpensive opto-electronic components were employed to analyse the antioxidant capacity of several bottled tea performing diphenylpicryl-hydrazyl (DPPH) tests. A dedicated python software allowed the execution of the analysis controlling the device through a small LCD touch screen or remotely through secure connections with other devices. The rRaspberry Pi-based measurements were compared with a research-grade spectrophotometer showing excellent correlation (R2 = 0.9996) and no significant differences (p < 0.05) in the range of measured values. We strongly believe that this approach could support diagnostics progress in resource-poor countries and open new opportunities in research and education
Device for interfacing filamentous or fibrous structures with a real or simulated biological tissue
No full textA device for interfacing at least one filamentous structure, with real or simulated biological tissue, comprising at least one body (10, 20) for anchoring the filamentous structure, said device being characterized in that said body (10, 20) comprises: at least one capstan (12, 22, 22', 22'), said capstan (12, 22, 22') being configured for wrapping the filamentous structure; at least one porous portion (13, 13', 24) having a trabecular structure (300); and system for regeneration, or repair, or replacement, or simulation of tendon and/or ligamentous tissue comprising said device and at least one filamentous structure comprising a plurality of nanofiber assemblies obtained by electrospinning, said plurality of assemblies being arranged to form a single bundle; said bundle being wrapped to the capstan (12)
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