HER2-expressing cancers currently benefit from targeted therapies, including monoclonal antibodies and antibody-drug conjugates that specifically bind to the extracellular domain of the receptor. Peptides targeting HER2 represent promising candidates for the development of alternative molecular drugs. In this study, we report a dimeric version of the previously validated A9 peptide as a ligand specifically targeting HER2. The novel A9-PEG-A9 conjugate consists of two A9 peptides whose N-terminal amino groups are linked via a polyethylene glycol chain. It was synthesized using a solvent-free protocol and validated as an improved ligand, demonstrating enhanced water solubility and increased affinity for the model receptor HER2-DIVMP, as determined by the fluorescence spectroscopy titration method.
A green synthetic protocol to add a chemical function to a fully deprotected peptide to obtain a bioactive and/or fluorescent-labeled conjugate is reported. A range of S-conjugation reactions promoted by the commercially available LTA zeolite to introduce different substituents on peptide cysteine residues has been shown to take place in the solid state or in the presence of minimal amounts of organic solvent, with yields that are comparable to those of standard solution methods. The additional advantage of the procedure consists of easing the work up, for which green solvents, such as aqueous systems, can be employed. The protocol is implemented with microwave irradiation to shorten the reaction time as dielectric heating increases the diffusion rates of the mechanically milled reactants.
The current coronavirus disease-2019 (COVID-19) pandemic is due to the novel coronavirus SARS-CoV-2. The scientific community has mounted a strong response by accelerating research and innovation, and has quickly set the foundation for understanding the molecular determinants of the disease for the development of targeted therapeutic interventions. The replication of the viral genome within the infected cells is a key stage of the SARS-CoV-2 life cycle. It is a complex process involving the action of several viral and host proteins in order to perform RNA polymerization, proofreading and final capping. This review provides an update of the structural and functional data on the key actors of the replicatory machinery of SARS-CoV-2, to fill the gaps in the currently available structural data, which is mainly obtained through homology modeling. Moreover, learning from similar viruses, we collect data from the literature to reconstruct the pattern of interactions among the protein actors of the SARS-CoV-2 RNA polymerase machinery. Here, an important role is played by co-factors such as Nsp8 and Nsp10, not only as allosteric activators but also as molecular connectors that hold the entire machinery together to enhance the efficiency of RNA replication.
Here we report on the most recent updates on experimental drugs successfully employed
in the treatment of the disease caused by SARS-CoV-2 coronavirus, also referred to as
COVID-19 (COronaVIrus Disease 19). In particular, several cases of recovered patients have
been reported after being treated with lopinavir/ritonavir (which is widely used to treat human
immunodeficiency virus (HIV) infection) in combination with the anti-flu drug oseltamivir. In
addition, remdesivir, which has been previously administered to Ebola virus patients, has also
proven effective in the U.S. against coronavirus, while antimalarial chloroquine and hydroxychloroquine,
favipiravir and co-administered darunavir and umifenovir (in patient therapies)
were also recently recorded as having anti-SARS-CoV-2 effects. Since the recoveries/deaths
ratio in the last weeks significantly increased, especially in China, it is clear that the experimental
antiviral therapy, together with the availability of intensive care unit beds in hospitals
and rigorous government control measures, all play an important role in dealing with this virus.
This also stresses the urgent need for the scientific community to devote its efforts to the
development of other more specific antiviral strategies.
The first outbreak of COVID-19 in Italy occurred during the second half of February 2020 in some areas in the North of the country. Due to the high contagiousness of the infection, further spread by asymptomatic people,
Italy has become in a few weeks the country with the greatest number of infected people in the world. The large number of severe cases among infected people in Italy led to the hospitalization of thousands of patients, with a heavy burden on the National Health Service.
Methods
We analyzed data provided daily by Italian Authorities for the period from 24 February 2020 to 30 March 2020. Considering such information, we developed a forecast model in real-time, based on the cumulative log-logistic distribution.
Results
A total of 101,739 infected individuals were confirmed until 30 March 2020, of which 14,620 recovered or discharged, and 11,591 deaths. Until the same date patients quarantined at home were 43,752, whereas hospitalized patients were 31,776, of which 3981 in intensive care. The active cases (i.e. the number of patients not yet recovered until that date) were 75,528. The forecast model estimated a number of infected persons for Italy of 234,000 about, and a duration of the epidemic of approximately 4 months.
Conclusions
One month after the first outbreaks there seemed to be the first signs of a decrease in the number of infections, showing that we could be now facing the descending phase of the epidemic. The forecast obtained thanks to our model could be used by decision-makers to implement coordinative and collaborative efforts in order to control the epidemic.
The pandemic due to novel Coronavirus must be a warning for all countries worldwide, regarding a rapid and complete dissemination of information, surveillance, health organization, and cooperation among the states.
The non-enzymatic deamidation of asparagine residues in proteins is a widely occurring reaction, both in vivo and in vitro. Although the importance of this process is commonly recognised, only little structural information is available on it. In order to evaluate the structural effects of this reaction in proteins, we have determined the crystal structure of a ribonuclease A derivative in which asparagine 67 has been replaced by an isoaspartyl residue, as a consequence of an in vitro deamidation reaction. The overall structure of the model, refined to a crystallographic X-factor of 0.159 at a resolution of 1.9 Å, is very similar to that of the native protein, but considerable deviations are observed in the region delimited by the disulphide bridge 65-72. In particular, the insertion of an extra methylene group in the main chain at residue 67 breaks up the hydrogen bond network that makes this region rather rigid in ribonuclease A. On the basis of the structure observed, some of the slightly but significantly different properties of this deamidated derivative, with respect to the native enzyme, can be explained.
The synthesis of poly[N,N-bis(3-aminopropyl)glycine] (PAPGly) dendrons Gd-based contrast agents (GdCAs) via an orthogonal protection of the different functional groups and an activation/coupling strategy wherein a specific number of synthetic steps add a generation to the existing dendron has been described. The aim of this protocol is to build up two different generations of dendrons (G-0 or dendron's core, and G-1) with peripheral NH(2) groups to conjugate a 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (DO3A) derivative and afterwards to chelate with Gd(3+) paramagnetic ions. These complexes, which have a well-defined molecular weight, are of relevance to MRI as an attempt to gain higher (1) H relaxivity by slowing down the rotation of molecule compared to monomeric Gd(III) complexes used as contrast agents and to increase the number of paramagnetic centers present in one molecular structure. From the study of their water (1) H longitudinal relaxation rate at different magnetic fields (NMRD, Nuclear Magnetic Relaxation Dispersion) and by evaluating the variable temperature (17) O-NMR data we determined the parameters characterizing the water exchange rate and the rotational correlation time of each complex, both affecting (1) H relaxivity. Furthermore, these two novel PAPGly GdCAs were objects of i) an in vivo study to determine their biodistributions in healthy C57 mice at several time points, and ii) the Dynamic Contrast-Enhanced MRI (DCE-MRI) approach to assess their contrast efficiency measured in the tumor region of C57BL/6 mice transplanted subcutaneously with B16-F10 melanoma cells. The aim of the comparison of these two dendrons GdCAs, having different molecular weights (MW), is to understand how MW and relaxivity may influence the contrast enhancement capabilities in vivo at low magnetic field (1 T). Significant contrast enhancement was observed in several organs (vessel, spleen and liver), already at 5 min post-injection, for the investigated CAs. Moreover, these CAs induced a marked contrast enhancement in the tumor region, thanks to the enhanced permeability retention effect of those macromolecular structures.
Granato L, Longo D, Boutry S, Vander Elst L, Henoumont C, Aime S, Muller RN, Laurent S
In order to evaluate 131I metaiodobenzylguanidine (MIBG) uptake in patients with benign or malignant paragangliomas, 28 patients (14 men and 14 women, mean age 37 ± 10 years) with benign (no. = 15; group 1) or malignant (no. = 13; group 2) tumors underwent MIBG scintigraphy. A total of 110 lesions (20 benign and 90 malignant) were studied. In all patients histologic disease confirmation was obtained. MIBG uptake was quantified on 48 hours' images (Kodak NMC-1 films) using a photographic densitometer. The optical densities of tumor and adjacent or contralateral normal tissue were used to calculate the MIBG uptake intensity ratio for each lesion. In group 1, all patients exhibited 1 or 2 lesions with abnormal MIBG uptake. In group 2, all patients had 1 to 28 abnormal foci of MIBG uptake. In the patients with 2 or more lesions, the average MIBG uptake intensity ratio was calculated. MIBG uptake intensity ratio was significantly higher in malignant than in benign paragangliomas (5.2 ± 2.4 vs 2.9 ± 1.4, p < 0.01). Since MIBG uptake in paragangliomas reflects the intratumoral concentration of catecholamines, higher MIBG uptake in malignant lesions suggests a greater amount of stored catecholamines in these tumors. In conclusion, 131I MIBG scintigraphy may be useful to distinguish benign from malignant paragangliomas.
L'Istituto di Biostrutture e Bioimmagini (IBB) del Consiglio Nazionale delle Ricerche (CNR) ha 100 unità di personale distribuite nelle sedi di Napoli e Torino (70 ricercatori/tecnologi) e svolge attività di ricerca traslazionale per lo sviluppo nuovi strumenti per la prevenzione, la diagnosi e terapie a bersaglio molecolare.
Per realizzare questi obiettivi ricercatori che studiano le biomolecole da un punto di vista strutturale e funzionale collaborano con esperti di imaging preclinico che studiano modelli cellulari ed animali di malattie umane e ricercatori clinici che effettuano sperimentazioni nell'uomo.
Le attività di ricerca comprendono la ricerca di base, un laboratorio per l’Imaging preclinico dei piccoli animali da laboratorio ed aree di ricerca clinica svolte in collaborazione con Università ed altri enti di ricerca. La combinazione di competenze inerenti la chimica teorica e la progettazione e la sperimentazione, sia in vitro che in vivo, di nuovi agenti diagnostici e terapeutici con le competenze in molteplici modalità di imaging (tra cui MRI, imaging ottico, PET / SPECT, ecografia, TC) forniscono le basi interdisciplinari per realizzare una ricerca innovativa nel campo dell'imaging molecolare e della terapia personalizzata.
Un altro settore di ricerca sviluppato dall’IBB è rappresentato dall’e-Health. L’attività ha lo scopo di realizzare sistemi software open-source, costituiti da modelli, servizi e strumenti di supporto alla diagnosi, terapia e follow-up, nonché per la gestione innovativa dei processi sanitari.
L'Istituto fa parte del nodo italiano del Forum strategico europeo sulle infrastrutture di ricerca denominato EuroBioimaging (EuBi). EuBi è una large-scale facility a livello pan-europeo in grado di fornire a ricercatori provenienti da tutta Europa il libero accesso alle più innovative tecnologie di imaging biologico e medicale.
L’attività fondamentale dell’Istituto di Biostrutture e Bioimmagini è costituita dalle seguenti aree di ricerca:
• Design, sintesi, espressione e caratterizzazione strutturale di molecole di interesse biologico, e loro interazioni con ioni metallici. Applicazioni in campo diagnostico e terapeutico.
• Tecnologie biochimiche e biostrutture;
• Tecnologie biochimiche finalizzate alla diagnostica per immagini;
• Diagnostica per immagini e radioterapia;
• Imaging molecolare preclinico e clinico. Nuovi agenti diagnostici/teragnostici per Imaging Molecolare;
• Sviluppo di soluzioni tecnologiche innovative di e-health, con particolare attenzione alla tematiche della telemedicina e della diagnosi assistita.