Biomechanical defects and rescue of cardiomyocytes expressing pathologic nuclear lamins

Given the clinical impact of LMNA cardiomyopathies, understanding lamin function will fulfill a clinical need and will lead to advancement in the treatment of heart failure. A multidisciplinary approach combining cell biology, atomic force microscopy (AFM) and molecular modeling was used to analyze the biomechanical properties of human lamin A/C gene (LMNA) mutations (E161K, D192G, N195K) using an in vitro neonatal rat ventricular myocyte (NRVM) model

Size and shape matter! a multiscale molecular simulation approach to polymer nanocomposites

Multiscale molecular modelling (MsM) techniques are applied in many fields of material science, but it is particularly important in the polymer field, due to the wide range of phenomena occurring at different scales which influence the ultimate properties of the materials. In this context, MsM plays a crucial role in the design of new materials whose properties are influenced by the structure at the nanoscale. In this work we present the application of a multiscale molecular modelling procedure to characterize a different set of polymer-based nanocomposites (PNCs) obtained with full/partial dispersion of different nanofillers in different polymeric matrices. This approach relies on a step-by step message-passing technique from atomistic to mesoscale to finite element level, and the calculated results are compared to available experimental evidence. In detail, 13 PNC systems have been studied by different molecular modelling methods, such as atomistic molecular mechanics and molecular dynamics, mesoscale dissipative particles dynamics, and macroscale finite element methods, and their mechanical, thermal and barrier properties have been predicted in agreement with the available experimental data.All authors gratefully acknowledge the generous financial support to their work received in the framework of the 6th European Commission Framework Program Integrated Project "MultiHybrids'' (grant 026685-2IP). DRN also wishes to acknowledge the financial support from CONACYT Mexico (grant no. 146624)

Propellanes as Rigid Scaffolds for the Stereodefined Attachment of σ-Pharmacophoric Structural Elements to Achieve σ Affinity

Following the concept of conformationally restriction of ligands to achieve high receptor affinity, we exploited the propellane system as rigid scaffold allowing the stereodefined attachment of various substituents. Three types of ligands were designed, synthesized and pharmacologically evaluated as σ1 receptor ligands. Propellanes with (1) a 2-methoxy-5-methylphenylcarbamate group at the “left” five-membered ring and various amino groups on the “right” side; (2) benzylamino or analogous amino moieties on the “right” side and various substituents at the left five-membered ring and (3) various urea derivatives at one five-membered ring were investigated. The benzylamino substituted carbamate syn,syn-4a showed the highest σ1 affinity within the group of four stereoisomers emphasizing the importance of the stereochemistry. The cyclohexylmethylamine 18 without further substituents at the propellane scaffold revealed unexpectedly high σ1 affinity (Ki = 34 nM) confirming the relevance of the bioisosteric replacement of the benzylamino moiety by the cyclohexylmethylamino moiety. Reduction of the distance between the basic amino moiety and the “left” hydrophobic region by incorporation of the amino moiety into the propellane scaffold resulted in azapropellanes with particular high σ1 affinity. As shown for the propellanamine 18, removal of the carbamate moiety increased the σ1 affinity of 9a (Ki = 17 nM) considerably. Replacement of the basic amino moiety by H-bond forming urea did not lead to potent σ ligands. According to molecular dynamics simulations, both azapropellanes anti-5 and 9a as well as propellane 18 adopt binding poses at the σ1 receptor, which result in energetic values correlating well with their different σ1 affinities. The affinity of the ligands is enthalpy driven. The additional interactions of the carbamate moiety of anti-5 with the σ1 receptor protein cannot compensate the suboptimal orientations of the rigid propellane and its N-benzyl moiety within the σ1 receptor-binding pocket, which explains the higher σ1 affinity of the unsubstituted azapropellane 9a

\u3b2-catenin in Desmoid-Type Fibromatosis: deep insights on the role of T41A and S45F mutations on protein structure and gene expression

Desmoid- type fibromatosis (DF) is a rare mesenchymal lesion with high risk of local recurrence. Specific \u3b2-catenin mutations (S45F) appeared to be related to this higher risk compared to T41A mutated or wild type (WT). We explored the influence of both mutations and WT on structure stability and affinity of \u3b2-catenin for \u3b1-catenin and the pattern of gene expression that may influence DF behavior. Using 33 surgically resected primary DFs harboring T41A (n=14), S45F (n=10) or WT (n=9), we performed a comparative molecular analysis by protein/protein interaction modeling, gene expression by DASL microarrays, human inflammation gene panel and assessment of immune system-based biomarkers by immunohistochemistry. Mutated proteins were more stable than WT and formed a weaker complex with \u3b1-catenin. Consensus unsupervised gene clustering revealed the presence of two DF group- mutated (T41A+S45F) and WT (p= 0.0047). The gene sets "Inflammatory- Defense- Humoral-Immune Response" and "Antigen Binding" were significantly enriched in T41A. The deregulation of 16 inflammation-related genes was confirmed. Low numbers of T- cells and TAM infiltrating the tumors and low/absent PD-1/PD-L1 expression were also identified. We demonstrated that mutated DFs (T41A or S45F) and WT are two distinct molecular subgroups with regard to \u3b2-catenin stability, \u3b1-catenin affinity and gene expression profiling. A different inflammation signature characterized the two mutated groups, suggesting a mediation either by T41A or S45F. Finally, all mutated cases showed a low number of TIL and TAM cells and a low or absent expression of PD-1 and PD-L1 consistent with \u3b2-catenin activation insensitive to check-point blockade

Design and Synthesis of Phosphonoacetic Acid (PPA) Ester and Amide Bioisosters of Ribofuranosylnucleoside Diphosphates as Potential Ribonucleotide Reductase Inhibitors and Evaluation of Their Enzyme Inhibitory, Cytostatic and Antiviral Activity

Continuing our investigations on inhibitors of ribonucleotide reductase (RNR), the crucial enzyme that catalyses the reduction of ribonu-cleotides to deoxyribonucleotides, we have now prepared and evaluated 5′-phosphonoacetic acid, amide and ester analogues of adenosine, uridine and cytidine with the aim to verify both substrate specificity and contribution to biological activity of diphosphate mimic moieties. A molecular modelling study has been conducted on the RNR R1 subunit, in order to verify the possible interaction of the proposed bioisosteric moieties. The study compounds were finally tested on the recombinant murine RNR showing a degree of inhibition that ranged from 350 μM for the UDP analogue 5′-deoxy-5′- N-(phosphon-acetyl)uridine sodium salt (amide) to 600 μM for the CDP analogue 5′- O-[(diethyl-phosphon)acetyl]cytidine (ester). None of the tested compounds displayed noteworthy cytostatic activity at 100–500 μM concentrations, whereas ADP analogue 5′- N-[(diethyl-phosphon) acetyl]adenosine (amide) and 5′-deoxy-5′- N-(phos-phon-acetyl)adenosine sodium salt (amide) showed a moderate inhibitory activity (EC50: 48 μM) against HSV-2 and a modest inhibitory activity (EC50: 110 μM) against HIV-1, respectively