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•Molecular dynamics simulation was carried out to study the effects of Y181C and K103N reverse transcriptase mutations on DAPYs and IASs binding mode.•Trajectories analysis confirmed ...the crucial role of inhibitors flexibility to retain fruitful binding modes versus mutated RT.•IASs binding plasticity sounds to be peculiar.
The emergence of HIV-1 drugs resistant stains remains of pivotal interest in relation to drugs development. Non nucleoside reverse transcriptase inhibitors proven to be very effective versus HIV-1 wild type but, with the only exception of diarylpyrimidines (e.g., etravirine, 1), were featured by high-level resistance versus mutated RT.
The effects of two of the most clinically relevant RT mutations (Y181C; K103N) were studied by a computational approach. This involved molecular dynamics, principal components analysis (PCA) and residue interactions networks (RINs). The methodology was applied to 1 and to Indolyl Aryl Sulphones (IASs 2 and 3), a class of potent RT inhibitors active also versus mutated RT forms. The molecular insight from this study was in accordance with the proposed mechanism of resistance for studied mutations and it might be useful in the design of novel RT inhibitors with high ligand efficacy on resistant strains.
Belonging to cellular solids subclasses, lattice structures have recently obtained much interest in the lightweight engineering sector thanks to the potential of their specific structural properties. ...This investigation explores the mechanical properties of lattice cells selected for their energy absorption capacity while considering strut orientation angle, vertical reinforcement, combination of cells and aspect ratio as geometrical and topological parameters. Truss lattices are examined given their excellent results from the point of view of energy absorption behavior. While non-linear static analyses are used to determine both volumetric and specific energy absorption, dynamic calculations are employed to identify the densification point and assess on the crashing load efficiency of the considered cells. This contribution aims at providing a deeper understanding of the mechanical behavior of lattice structures in order to provide construction guidelines that can be employed in rapid prototyping and design of lightweight structures.
The enterovirus is a genus of single-stranded, highly diverse positive-sense RNA viruses, including Human Enterovirus A-D and Human Rhinovirus A-C species. They are responsible for numerous diseases ...and some infections can progress to life-threatening complications, particularly in children or immunocompromised patients. To date, there is no treatment against enteroviruses on the market, except for polioviruses (vaccine) and EV-A71 (vaccine in China). Following a decrease in enterovirus infections during and shortly after the (SARS-Cov2) lockdown, enterovirus outbreaks were once again detected, notably in young children. This reemergence highlights on the need to develop broad-spectrum treatment against enteroviruses. Over the last year, our research team has identified a new class of small-molecule inhibitors showing anti-EV activity. Targeting the well-known hydrophobic pocket in the viral capsid, these compounds show micromolar activity against EV-A71 and a high selectivity index (SI) (5h: EC50, MRC-5 = 0.57 μM, CC50, MRC-5 >20 μM, SI > 35; EC50, RD = 4.38 μM, CC50, RD > 40 μM, SI > 9; 6c: EC50, MRC-5 = 0.29 μM, CC50, MRC-5 >20 μM, SI > 69; EC50, RD = 1.66 μM, CC50, RD > 40 μM, SI > 24; Reference: Vapendavir EC50, MRC-5 = 0.36 μM, CC50, MRC-5 > 20 μM, EC50, RD = 0.53 μM, CC50, RD > 40 μM, SI > 63). The binding mode of these compounds in complex with enterovirus capsids was analyzed and showed a series of conserved interactions. Consequently, 6c and its derivatives are promising candidates for the treatment of enterovirus infections.
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•High-yielding reaction enables us to make a wide range of modulations thanks to 2 optimized synthesis pathways/strategies.•Each synthesized compound is first docked within our target and then evaluated on 2 cell lines (Rhabdomyosarcoma and MRC-5).•5h and 6c effectively inhibits EV-A71 and are neither cytotoxic nor clastogenic nor aneugenic compounds.
Red and blue arrows show the rivaroxaban and convulxin (CVX) pathways respectively. Rivaroxaban binds the GPVI receptor, inhibits Nox2-derived oxidative stress and ultimately platelet Thromboxane A2 ...and isoprostanes production.
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Factor Xa (FXa) has been reported to activate platelet via interaction with glycoprotein (GP) VI but the underlying mechanism has not been fully elucidated. We investigated if Nox2-derived oxidative stress is implicated in FXa-induced platelet aggregation (PA), and the effect of a FXa inhibitor, namely rivaroxaban, with or without aspirin (ASA), on PA.
We performed an in vitro study measuring convulxin-induced PA, thromboxane (Tx) B2 and isoprostanes biosynthesis, soluble Nox2-dp (sNox2-dp), a marker of Nox2 activation, soluble GPVI (sGPVI) and PLA2 activation in platelets from healthy subjects (n = 5) added with and without a Nox2 inhibitor. The same variables were also examined in platelets treated with rivaroxaban (15–60 ng/ml), combined or less with ASA (25 µM).
Convulxin-stimulated platelets increased sGPVI, sNox2-dp, H2O2, eicosanoid biosynthesis and PLA2 phosphorylation, which were all inhibited by a Nox2 inhibitor. Rivaroxaban alone significantly reduced PA, sGPVI, TxB2 and isoprostanes biosynthesis, concomitantly with Syk, sNox2-dp and PLA2 activation in a dose-dependent fashion; a significant effect was achieved with 30 ng/ml rivaroxaban. Docking simulation analysis showed that rivaroxaban interacts with GPVI. In platelets co-incubated with ASA, rivaroxaban amplified the ASA antiplatelet effect, which was achieved with 30 ng/ml and prevalently attributable to Nox2 inhibition and impaired isoprostane biosynthesis.
Here we show that rivaroxaban, at concentrations achievable in human circulation, inhibits PA via GPVI interaction and eventually Nox2-mediated isoprostanes biosynthesis and amplifies the ASA antiplatelet effect.
Nuclear activated β-catenin plays a causative role in colorectal cancers (CRC) but remains an elusive therapeutic target. Using human CRC cells harboring different Wnt/β-catenin pathway mutations in ...APC/KRAS or β-catenin/KRAS genes, and both genetic and pharmacological knockdown approaches, we show that oncogenic β-catenin signaling negatively regulates the expression of NHERF1 (Na
/H
exchanger 3 regulating factor 1), a PDZ-adaptor protein that is usually lost or downregulated in early dysplastic adenomas to exacerbate nuclear β-catenin activity. Chromatin immunoprecipitation (ChIP) assays demonstrated that β-catenin represses NHERF1 via TCF4 directly, while the association between TCF1 and the Nherf1 promoter increased upon β-catenin knockdown. To note, the occurrence of a cytostatic survival response in settings of single β-catenin-depleted CRC cells was abrogated by combining NHERF1 inhibition via small hairpin RNA (shRNA) or RS5517, a novel PDZ1-domain ligand of NHERF1 that prevented its ectopic nuclear entry. Mechanistically, dual NHERF1/β-catenin targeting promoted an autophagy-to-apoptosis switch consistent with the activation of Caspase-3, the cleavage of PARP and reduced levels of phospho-ERK1/2, Beclin-1, and Rab7 autophagic proteins compared with β-catenin knockdown alone. Collectively, our data unveil novel β-catenin/TCF-dependent mechanisms of CRC carcinogenesis, also offering preclinical proof of concept for combining β-catenin and NHERF1 pharmacological inhibitors as a mechanism-based strategy to augment apoptotic death of CRC cells refractory to current Wnt/β-catenin-targeted therapeutics.
Most cancer cells switch their metabolism from mitochondrial oxidative phosphorylation to aerobic glycolysis to generate ATP and precursors for the biosynthesis of key macromolecules. The aerobic ...conversion of pyruvate to lactate, coupled to oxidation of the nicotinamide cofactor, is a primary hallmark of cancer and is catalyzed by lactate dehydrogenase (LDH), a central effector of this pathological reprogrammed metabolism. Hence, inhibition of LDH is a potential new promising therapeutic approach for cancer. In the search for new LDH inhibitors, we carried out a structure-based virtual screening campaign. Here, we report the identification of a novel specific LDH inhibitor, the pyridazine derivative 18 (RS6212), that exhibits potent anticancer activity within the micromolar range in multiple cancer cell lines and synergizes with complex I inhibition in the suppression of tumor growth. Altogether, our data support the conclusion that compound 18 deserves to be further investigated as a starting point for the development of LDH inhibitors and for novel anticancer strategies based on the targeting of key metabolic steps.
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•New pyridazine derivative 11 was discovered by virtual screening studies.•It inhibited proliferation of various cancer cells.•It showed a promising inhibition of LDHA activity.•It failed to inhibit cell proliferation of LDHA-deficient HCT116 cells.•It showed synergistic effect with inhibition of mitochondrial complex I.
Abstract
Aims
Recent studies reported that cAMP-binding protein Epac1-deficient mice were protected against various forms of cardiac stress, suggesting that pharmacological inhibition of Epac1 could ...be beneficial for the treatment of cardiac diseases. To test this assumption, we characterized an Epac1-selective inhibitory compound and investigated its potential cardioprotective properties.
Methods and results
We used the Epac1-BRET (bioluminescence resonance energy transfer) for searching for non-cyclic nucleotide Epac1 modulators. A thieno2,3-bpyridine derivative, designated as AM-001 was identified as a non-competitive inhibitor of Epac1. AM-001 has no antagonist effect on Epac2 or protein kinase A activity. This small molecule prevents the activation of the Epac1 downstream effector Rap1 in cultured cells, in response to the Epac1 preferential agonist, 8-CPT-AM. In addition, we found that AM-001 inhibited Epac1-dependent deleterious effects such as cardiomyocyte hypertrophy and death. Importantly, AM-001-mediated inhibition of Epac1 reduces infarct size after mouse myocardial ischaemia/reperfusion injury. Finally, AM-001 attenuates cardiac hypertrophy, inflammation and fibrosis, and improves cardiac function during chronic β-adrenergic receptor activation with isoprenaline (ISO) in mice. At the molecular level, ISO increased Epac1-G protein-coupled receptor kinase 5 (GRK5) interaction and induced GRK5 nuclear import and histone deacetylase type 5 (HDAC5) nuclear export to promote the activity of the prohypertrophic transcription factor, myocyte enhancer factor 2 (MEF2). Inversely, AM-001 prevented the non-canonical action of GRK5 on HDAC5 cytoplasmic shuttle to down-regulate MEF2 transcriptional activity.
Conclusion
Our study represents a ‘proof-of-concept’ for the therapeutic effectiveness of inhibiting Epac1 activity in cardiac disease using small-molecule pharmacotherapy.
Highlights • Resolution of three-dimensional viral structures in the PDB statistically analysed. • Evolution of structure-based methods in antiviral drug-discovery overviewed. • Different examples of ...the role of structural biology in the discovery and optimisation of new antivirals examined.
Long-term survivors of glioblastoma multiforme (GBM) are at high risk of developing second primary neoplasms, including leukemia. For these patients, the use of classic tyrosine kinase inhibitors ...(TKIs), such as imatinib mesylate, is strongly discouraged, since this treatment causes a tremendous increase of tumor and stem cell migration and invasion. We aimed to develop agents useful for the treatment of patients with GBM and chronic myeloid leukemia (CML) using an alternative mechanism of action from the TKIs, specifically based on the inhibition of tubulin polymerization. Compounds 7 and 25, as planned, not only inhibited tubulin polymerization, but also inhibited the proliferation of both GMB and CML cells, including those expressing the T315I mutation, at nanomolar concentrations. In in vivo experiments in BALB/cnu/nu mice injected subcutaneously with U87MG cells, in vivo, 7 significantly inhibited GBM cancer cell proliferation, in vivo tumorigenesis, and tumor growth, tumorigenesis and angiogenesis. Compound 7 was found to block human topoisomerase II (hTopoII) selectively and completely, at a concentration of 100 μM.
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•New 1-aryl-4-heterocyclyl-3-trimethoxylphenylpyrroles were synthesized.•Compounds were designed as inhibitors of tubulin polymerization.•Compounds 7 and 25 inhibited GBM and CML cell proliferation.•7 inhibited GBM cancer cell proliferation, in vivo tumorigenesis, and tumor angiogenesis.•7 blocked hTopoII selectively and completely at a concentration of 100 μM.
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