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Lipopolysaccharide exposure to macrophages induces an inflammatory response that is heavily regulated at the transcriptional and post-transcriptional levels. HuR (ELAVL1) is an RNA binding protein that binds and regulates the maturation and half-life of AU/U rich elements (ARE) containing cytokines and chemokines transcripts, mediating the LPS-induced response. Here we investigated how and to what extent small molecule tanshinone mimics (TMs) inhibiting HuR-RNA interaction counteract LPS stimulus in macrophages. We show TMs exist in solution in keto-enolic tautomerism and that, by molecular dynamic calculations, the orto quinone form is the bioactive species interacting with HuR and inhibiting its binding mode vs mRNA targets. A chemical blockage of the diphenolic, reduced form as a diacetate caused the loss of activity of TMsin vitrobut resulted to prodrug-like activityin vivo. The murine macrophage cell line RAW264.7 was treated with LPS and TMs, and the modulation of cellular LPS-induced response was monitored by RNA and Ribonucleoprotein immunoprecipitation sequencing. Correlation analyses indicated that LPS induced a strong coupling between differentially expressed genes and HuR-bound genes, and that TMs reduced such interactions. Functional annotation addressed a specific set of genes involved in chemotaxis and immune response, such asCxcl10, Il1b, Cd40, andFas, with a decreased association with HuR, a reduction of their expression and protein secretion. The same effect was observed in primary murine bone marrow-derived macrophages, andin vivoin an LPS induced peritonitis model, in which the serum level of Cxcl10 and Il1b was strongly reduced, endowing TMs such asTM7noxwith remarkable anti-inflammatory propertiesin vivo.

Chronic hepatitis B (CHB) is a major worldwide public health problem and novel anti-HBV therapies preventing liver disease progression to cirrhosis and hepatocellular carcinoma are urgently needed. Over the last several years, capsid assembly modulators (CAM) have emerged as clinically effective anti-HBV agents which can inhibit HBV replication in CHB patients. As part of a drug discovery program aimed at obtaining novel CAM endowed with high in vitro and in vivo antiviral activity, we identified a novel series of sulfamoylbenzamide (SBA) derivatives. Compound 10, one of the most in vitro potent SBA-derived CAM discovered to date, showed excellent pharmacokinetics in mice suitable for oral dosing. When studied in a transgenic mouse model of hepatic HBV replication, it was considerably more potent than NVR 3-778, the first sulfamoylbenzamide (SBA) CAM that entered clinical trials for CHB, at reducing viral replication in a dose-dependent fashion. We present herein the discovery process, the SAR analysis and the pre-clinical profile of this novel SBA CAM.

A new series of in vitro potent and highly selective histone methyl transferase enzyme G9a inhibitors was obtained. In particular, compound 2a, one the most potent G9a inhibitor identified, was endowed with >130-fold selectivity over GLP and excellent ligand efficiency. Therefore, it may represent a valuable tool compound to validate the role of highly selective G9a inhibitors in different pathological conditions. When 2a was characterized in vitro in cellular models of skeletal muscle differentiation, a relevant increase of myofibers’ size and reduction of the fibroadipogenic infiltration were observed, further confirming the therapeutic potential of selective G9a inhibitors for the treatment of Duchenne muscle dystrophy.

[Image: see text] Acid-sensing ion channels (ASICs) are a family of ion channels permeable to cations and largely responsible for the onset of acid-evoked ion currents both in neurons and in different types of cancer cells, thus representing a potential target for drug discovery. Owing to the limited attention ASIC2 has received so far, an exploratory program was initiated to identify ASIC2 inhibitors using diminazene, a known pan-ASIC inhibitor, as a chemical starting point for structural elaboration. The performed exploration enabled the identification of a novel series of ASIC2 inhibitors. In particular, compound 2u is a brain penetrant ASIC2 inhibitor endowed with an optimal pharmacokinetic profile. This compound may represent a useful tool to validate in animal models in vivo the role of ASIC2 in different neurodegenerative central nervous system pathologies.

Novel proapoptotic Smac mimics/IAPs inhibitors have been designed, synthesized and characterized. Computational models and structural studies (crystallography, NMR) have elucidated the SAR of this class of inhibitors, and have permitted further optimization of their properties. In vitro characterization (XIAP BIR3 and linker-BIR2-BIR3 binding, cytotox assays, early ADMET profiling) of the compounds has been performed, identifying one lead for further in vitro and in vivo evaluation.

The efficacy of taxane-based antitumor therapy is limited by several drawbacks which result in a poor therapeutic index. Thus, the development of approaches that favor selective delivery of taxane drugs (e.g., paclitaxel, PTX) to the disease area represents a truly challenging goal. On the basis of the strategic role of integrins in tumor cell survival and tumor progression, as well as on integrin expression in tumors, novel molecular conjugates were prepared where PTX is covalently attached to either cyclic AbaRGD (Azabicycloalkane-RGD) or AmproRGD (Aminoproline-RGD) integrin-recognizing matrices via structurally diverse connections. Receptor-binding assays indicated satisfactory-to-excellent α(V)β(3) binding capabilities for most conjugates, while in vitro growth inhibition assays on a panel of human tumor cell lines revealed outstanding cell sensitivity values. Among the nine conjugate ensemble, derivative 21, bearing a robust triazole ring connected to ethylene glycol units by an amide function and showing excellent cell sensitivity properties, was selected for in vivo studies in an ovarian carcinoma model xenografted in immunodeficient mice. Remarkable antitumor activity was attained, superior to that of PTX itself, which was associated with a marked induction of aberrant mitoses, consistent with the mechanism of action of spindle poisons. Overall, the novel cRGD-PTX conjugates disclosed here represent promising candidates for further advancement in the domain of targeted antitumor therapy.

Novel pro-apoptotic, homo- and heterodimeric Smac mimetics/IAPs inhibitors based on the N-AVPI-like 4-substituted 1-aza-2-oxobicyclo[5.3.0]decane scaffold were prepared from monomeric structures connected through a head-head (8), tail-tail (9) or head-tail (10) linker. The selection of appropriate decorating functions for the scaffolds, and of rigid and flexible linkers connecting them, is described. The synthesis, purification and analytical characterization of each prepared dimer 8-10 is thoroughly described.

We report the synthesis of novel chelates of Gd and (68)Ga with DPTA, DOTA, HP-DOA3, as well as with AAZTA, a novel chelating agent developed by our research group. These chelating agents were appropriately conjugated, prior to metal complexation, with DB58, an RGD peptidomimetic, conformationally constrained on an azabicycloalkane scaffold and endowed with high affinity for integrin α(ν)β(3) . Because α(ν)β(3) is involved in neo-angiogenesis in solid tumors and is also directly expressed in cancer cells (e.g. glioblastomas, melanomas) and ovarian, breast, and prostate cancers, these constructs could prove useful as molecular imaging probes in cancer diagnosis by MRI or PET techniques. Molecular modeling, integrin binding assays, and relaxivity assessments allowed the selection of compounds suitable for multiple expression on dendrimeric or nanoparticulate structures. These results also led us to an exploratory investigation of (68)Ga complexation for the promising (68)Ga-PET technique; the AAZTA complex 15((68)Ga) exhibited uptake in a xenograft model of glioblastoma, suggesting potentially useful developments with new probes with improved affinity.

The lantibiotic 97518, produced by a Planomonospora sp., was reported as a 2194 Da polypeptide comprising 24 amino acid residues with five thioether bridges. It was assigned to the mersacidin subgroup of type B lantibiotics by Castiglione et al. (Biochemistry 2007, 46, 5884-5897) and named planosporicin. New analytical, chemical, and genetic data and reinterpretation of the published NMR chemical shifts enable structure revision of 97518. The resulting revision of the 97518 structure involves both a shift of two amino acids and a reorganization of two thioether bridges. With this revision, the lantibiotic 97518 becomes a clear member of the nisin subgroup of compounds.