Characterization of GEXP15 as a Potential Regulator of Protein Phosphatase 1 in Plasmodium falciparum.

The Protein Phosphatase type 1 catalytic subunit (PP1c) (PF3D7_1414400) operates in combination with various regulatory proteins to specifically direct and control its phosphatase activity. However, there is little information about this phosphatase and its regulators in the human malaria parasite, Plasmodium falciparum. To address this knowledge gap, we conducted a comprehensive investigation into the structural and functional characteristics of a conserved Plasmodium-specific regulator called Gametocyte EXported Protein 15, GEXP15 (PF3D7_1031600). Through in silico analysis, we identified three significant regions of interest in GEXP15: an N-terminal region housing a PP1-interacting RVxF motif, a conserved domain whose function is unknown, and a GYF-like domain that potentially facilitates specific protein-protein interactions. To further elucidate the role of GEXP15, we conducted in vitro interaction studies that demonstrated a direct interaction between GEXP15 and PP1 via the RVxF-binding motif. This interaction was found to enhance the phosphatase activity of PP1. Additionally, utilizing a transgenic GEXP15-tagged line and live microscopy, we observed high expression of GEXP15 in late asexual stages of the parasite, with localization predominantly in the nucleus. Immunoprecipitation assays followed by mass spectrometry analyses revealed the interaction of GEXP15 with ribosomal- and RNA-binding proteins. Furthermore, through pull-down analyses of recombinant functional domains of His-tagged GEXP15, we confirmed its binding to the ribosomal complex via the GYF domain. Collectively, our study sheds light on the PfGEXP15-PP1-ribosome interaction, which plays a crucial role in protein translation. These findings suggest that PfGEXP15 could serve as a potential target for the development of malaria drugs.

Phenothiazine- and Carbazole-Cyanochalcones as Dual Inhibitors of Tubulin Polymerization and Human Farnesyltransferase.

In the search for innovative approaches to cancer chemotherapy, a chemical library of 49 cyanochalcones, 1a-r, 2a-o, and 3a-p, was designed as dual inhibitors of human farnesyltransferase (FTIs) and tubulin polymerization (MTIs) (FTIs/MTIs), two important biological targets in oncology. This approach is innovative since the same molecule would be able to interfere with two different mitotic events of the cancer cells and prevent these cells from developing an emergency route and becoming resistant to anticancer agents. Compounds were synthesized by the Claisen-Schmidt condensation of aldehydes with N-3-oxo-propanenitriles under classical magnetic stirring and under sonication. Newly synthesized compounds were screened for their potential to inhibit human farnesyltransferase, tubulin polymerization, and cancer cell growth in vitro. This study allowed for the identification of 22 FTIs and 8 dual FTIs/MTIs inhibitors. The most effective molecule was carbazole-cyanochalcone 3a, bearing a 4-dimethylaminophenyl group (IC50 (h-FTase) = 0.12 µM; IC50 (tubulin) = 0.24 µM) with better antitubulin activity than the known inhibitors that were previously reported, phenstatin and (-)-desoxypodophyllotoxin. The docking of the dual inhibitors was realized in both the active site of FTase and in the colchicine binding site of tubulin. Such compounds with a dual inhibitory profile are excellent clinical candidates for the treatment of human cancers and offer new research perspectives in the search for new anti-cancer drugs.

Functional genomics uncovers the transcription factor BNC2 as required for myofibroblastic activation in fibrosis.

Tissue injury triggers activation of mesenchymal lineage cells into wound-repairing myofibroblasts, whose unrestrained activity leads to fibrosis. Although this process is largely controlled at the transcriptional level, whether the main transcription factors involved have all been identified has remained elusive. Here, we report multi-omics analyses unraveling Basonuclin 2 (BNC2) as a myofibroblast identity transcription factor. Using liver fibrosis as a model for in-depth investigations, we first show that BNC2 expression is induced in both mouse and human fibrotic livers from different etiologies and decreases upon human liver fibrosis regression. Importantly, we found that BNC2 transcriptional induction is a specific feature of myofibroblastic activation in fibrotic tissues. Mechanistically, BNC2 expression and activities allow to integrate pro-fibrotic stimuli, including TGFß and Hippo/YAP1 signaling, towards induction of matrisome genes such as those encoding type I collagen. As a consequence, Bnc2 deficiency blunts collagen deposition in livers of mice fed a fibrogenic diet. Additionally, our work establishes BNC2 as potentially druggable since we identified the thalidomide derivative CC-885 as a BNC2 inhibitor. Altogether, we propose that BNC2 is a transcription factor involved in canonical pathways driving myofibroblastic activation in fibrosis.

SINAPs: A Software Tool for Analysis and Visualization of Interaction Networks of Molecular Dynamics Simulations.

As long as the structural study of molecular mechanisms requires multiple molecular dynamics reflecting contrasted bioactive states, the subsequent analysis of molecular interaction networks remains a bottleneck to be fairly treated and requires a user-friendly 3D view of key interactions. Structural Interaction Network Analysis Protocols (SINAPs) is a proprietary python tool developed to (i) quickly solve key interactions able to distinguish two protein states, either from two sets of molecular dynamics simulations or from two crystallographic structures, and (ii) render a user-friendly 3D view of these key interactions through a plugin of UCSF Chimera, one of the most popular open-source viewing software for biomolecular systems. Through two case studies, glucose transporter-1 (GLUT-1) and A2A adenosine receptor (A2AR), SINAPs easily pinpointed key interactions observed experimentally and relevant for their bioactivities. This very effective tool was thus applied to identify the amino acids involved in the molecular enzymatic mechanisms ruling the activation of an immunomodulator drug candidate, P28 glutathione-S-transferase (P28GST). SINAPs is freely available at https://github.com/ParImmune/SINAPs.

In vitro and in silico approach to study the hormonal activities of the alternative plasticizer tri-(2-ethylhexyl) trimellitate TEHTM and its metabolites.

Tri-(2-ethylhexyl) trimellitate (TEHTM) is a plasticizer for polyvinyl chloride (PVC) material used in medical devices. It is an alternative to di-(2-ethylhexyl) phthalate (DEHP), a well-known reprotoxic and endocrine disruptor. As plasticizers are known to easily migrate when in contact with fatty biological fluids, patient exposure to TEHTM is highly probable. However, there is currently no data on the potential endocrine-disrupting effects of its human metabolites. To evaluate the effects of TEHTM metabolites on endocrine activity, they were first synthesized and their effects on estrogen, androgen and thyroid receptors, as well as steroid synthesis, were investigated by combining in vitro and in silico approaches. Among the primary metabolites, only 4-MEHTM (4-mono-(2-ethylhexyl) trimellitate) showed agonist activities on ERs and TRs, while three diesters were TR antagonists at non-cytotoxic concentrations. These results were completed by docking experiments which specified the ER and TR isoforms involved. A mixture of 2/1-MEHTM significantly increased the estradiol level and reduced the testosterone level in H295R cell culture supernatants. The oxidized secondary metabolites of TEHTM had no effect on ER, AR, TR receptors or on steroid hormone synthesis. Among the fourteen metabolites, these data showed that two of them (4-MEHTM and 2/1-MEHTM) induced effect on hormonal activities in vitro. However, by comparing the concentrations of the primary metabolites found in human urine with the active concentrations determined in bioassays, it can be suggested that the metabolites will not be active with regard to estrogen, androgen, thyroid receptors and steroidogenesis-mediated effects.

Polycyclic nitrogen heterocycles as potential thymidine phosphorylase inhibitors: synthesis, biological evaluation, and molecular docking study.

New polycyclic heterocycles were synthesised and evaluated as potential inhibitors of thymidine phosphorylase (TP). Inspired by the pharmacophoric pyrimidinedione core of the natural substrate, four series have been designed in order to interact with large empty pockets of the active site: pyrimidoquinoline-2,4-diones (series A), pyrimidinedione linked to a pyrroloquinoline-1,3-diones (series B and C), the polycyclic heterocycle has been replaced by a pyrimidopyridopyrrolidinetetraone (series D). In each series, the tricyclic nitrogen heterocyclic moiety has been synthesised by a one-pot multicomponent reaction. Compared to 7-DX used as control, 2d, 2l, 2p (series A), 28a (series D), and the open intermediate 30 showed modest to good activities. A kinetic study confirmed that the most active compounds 2d, 2p are competitive inhibitors. Molecular docking analysis confirmed the interaction of these new compounds at the active binding site of TP and highlighted a plausible specific interaction in a pocket that had not yet been explored.

Combretastatin A-4 sulfur-containing heterocyclic derivatives: Synthesis, antiproliferative activities and molecular docking studies.

Combretastatin A-4 inspired heterocyclic derivatives were synthesized and evaluated for their biological activities on tubulin polymerization and cell proliferation. Among the 19 described sulfur-containing compounds, derivatives (Z)-4h and (Z)-4j exhibited interesting in cellulo tubulin polymerization inhibition and antiproliferative activities with IC50 values for six different cell lines between 8 and 27 nM. Furthermore, in silico docking studies within the colchicine/CA-4 binding site of tubulin were carried out to understand the interactions of our products with the protein target. The effects on the cell cycle of follicular lymphoma cells were also investigated at 1-10 nM concentrations showing that apoptotic processes occurred.

Comparative Effects of Di-(2-ethylhexyl)phthalate and Di-(2-ethylhexyl)terephthalate Metabolites on Thyroid Receptors: In Vitro and In Silico Studies.

Plasticizers added to polyvinylchloride (PVC) used in medical devices can be released into patients' biological fluids. Di-(2-ethylhexyl)phthalate (DEHP), a well-known reprotoxic and endocrine disruptor, must be replaced by alternative compounds. Di-(2-ethylhexyl) terephthalate (DEHT) is an interesting candidate due to its lower migration from PVC and its lack of reprotoxicity. However, there is still a lack of data to support the safety of its human metabolites with regard to their hormonal properties in the thyroid system. The effects of DEHT metabolites on thyroid/hormone receptors (TRs) were compared in vitro and in silico to those of DEHP. The oxidized metabolites of DEHT had no effect on T3 receptors whereas 5-hydroxy-mono-(ethylhexyl)phthalate (5-OH-MEHP) appeared to be primarily an agonist for TRs above 0.2 µg/mL with a synergistic effect on T3. Monoesters (MEHP and mono-(2-ethylhexyl)terephthalate, MEHT) were also active on T3 receptors. In vitro, MEHP was a partial agonist between 10 and 20 µg/mL. MEHT was an antagonist at non-cytotoxic concentrations (2-5 µg/mL) in a concentration-dependent manner. The results obtained with docking were consistent with those of the T-screen and provide additional information on the preferential affinity of monoesters and 5-OH-MEHP for TRs. This study highlights a lack of interactions between oxidized metabolites and TRs, confirming the interest of DEHT.

Indolizine-phenothiazine hybrids as the first dual inhibitors of tubulin polymerization and farnesyltransferase with synergistic antitumor activity.

In the incessant search for innovative cancer control strategies, this study was devoted to the design, synthesis and pharmacological evaluation of dual inhibitors of farnesyltransferase and tubulin polymerization (FTI/MTIs). A series of indolizine-phenothiazine hybrids 16 (amides) and 17 (ketones) has been obtained in a 4-step procedure. The combination of the two heterocycles provided potent tubulin polymerization inhibitors with similar efficiency as the reference phenstatin and (-)-desoxypodophyllotoxin. Ketones 17 were also able to inhibit human farnesyltransferase (FTase) in vitro. Interestingly, three molecules 17c, 17d and 17f were very effective against both considered biological targets. Next, nine indolizine-phenothiazine hybrids 16c, 16f, 17a-f and 22b were evaluated for their cell growth inhibition potential on the NCI-60 cancer cell lines panel. Ketones 17a-f were the most active and displayed promising cellular activities. Not only they arrested the cell growth of almost all tested cancer cells, but they displayed cytotoxicity potential with GI50 values in the low nanomolar range. The most sensitive cell lines upon treatment with indolizine-phenothiazine hybrids were NCI-H522 (lung cancer), COLO-205 and HT29 (colon cancer), SF-539 (human glioblastoma), OVCAR-3 (ovarian cancer), A498 (renal cancer) and especially MDA-MB-435 (melanoma). Demonstrating the preclinical effectiveness of these dual inhibitors can be crucial. A single dual molecule could induce a synergy of antitumor activity, while increasing the effectiveness and reducing the toxicity of the classical combo treatments currently used in chemotherapy.

Ultrasounds-mediated 10-seconds synthesis of chalcones as potential farnesyltransferase inhibitors.

A broad range of chalcones and derivatives were easily and rapidly synthesized, following Claisen-Schmidt condensation of (hetero)aryl ketones and (hetero)aryl aldehydes using a ultrasound probe. A comparison was made with classical magnetic stirring experiments, and an optimization study was realized, showing lithium hydroxide to be the best basic catalyst of the studied condensations. By-products of the reactions (ß-hydroxy-ketone, diketones, and cyclohexanols) were also isolated. All compounds were evaluated in vitro for their ability to inhibit human farnesyltransferase, a protein implicated in cancer and rare diseases and on the NCI-60 cancer cell lines panel. Molecules showed inhibitory activity on the target protein and cytostatic effect on different cell lines with particular activity against MCF7, breast cancer cells.

Enhanced antitumor potential induced by chloroacetate-loaded benzophenones acting as fused tubulin-pyruvate dehydrogenase kinase 1 (PDHK1) ligands.

The majority of cancers detected every year are treated with anti-cancer compounds. Unfortunately, many tumors become resistant to antineoplastic drugs. One option is to use cocktails of compounds acting on different targets to try to overcome the resistant cells. This type of approach can produce good results, but is often accompanied by a sharp increase of associated side effects. The strategy presented herein focuses on the use of a single compound acting on two different biological targets enhancing potency and lowering the toxicity of the chemotherapy. In this light, the approach presented in the current study involves the dual inhibition of human pyruvate dehydrogenase kinase-1 (PDHK1) and tubulin polymerization using mono-, di- and tri-chloroacetate-loaded benzophenones and benzothiophenones. Synthesized molecules were evaluated in vitro on tubulin polymerization and on pyruvate dehydrogenase kinase 1. The cell cycle distribution after treatment of DA1-3b leukemic cells with active compounds was tested. Twenty-two benzo(thio)phenones have been selected by the National Cancer Institute (USA) for evaluation of their anti-proliferative potential against NCI-60 cancer cell lines including multidrug-resistant tumor cell lines. Seventeen molecules proved to be very effective in combating the growth of tumor cells exhibiting inhibitory activities up to nanomolar range. The molecular docking of best antitumor molecules in the study was realized with GOLD in the tubulin and PDHK1 binding sites, and allowed to understand the positioning of active molecules. Chloroacetate-loaded benzo(thio)phenones are dual targeted tubulin- and pyruvate dehydrogenase kinase 1 (PDHK1)-binding antitumor agents and exhibited superior antitumor activity compared to non-chlorinated congeners particularly on leukemia, colon, melanoma and breast cancer cell lines.

Pyroglutamide-Based P2X7 Receptor Antagonists Targeting Inflammatory Bowel Disease.

This report deals with the design, the synthesis, and the pharmacological evaluation of pyroglutamide-based P2X7 antagonists. A dozen were shown to possess improved properties, among which inhibition of YO-PRO-1/TO-PRO-3 uptake and IL1ß release upon BzATP activation of the receptor and dampening signs of DSS-induced colitis on mice, in comparison with reference antagonist GSK1370319A. Docking study and biological evaluation of synthesized compounds has highlighted new SAR, and low toxicity profiles of pyroglutamides herein described are clues for the finding of a usable h-P2X7 antagonist drug. Such a drug would raise the hope for a cure to many P2X7-dependent pathologies, including inflammatory, neurological, and immune diseases.

New piperazine multi-effect drugs prevent neurofibrillary degeneration and amyloid deposition, and preserve memory in animal models of Alzheimer's disease.

Alzheimer's Disease is a devastating dementing disease involving amyloid deposits, neurofibrillary tangles, progressive and irreversible cognitive impairment. Today, only symptomatic drugs are available and therapeutic treatments, possibly acting at a multiscale level, are thus urgently needed. To that purpose, we designed multi-effects compounds by synthesizing drug candidates derived by substituting a novel N,N'-disubstituted piperazine anti-amyloid scaffold and adding acetylcholinesterase inhibition property. Two compounds were synthesized and evaluated. The most promising hybrid molecule reduces both the amyloid pathology and the Tau pathology as well as the memory impairments in a preclinical model of Alzheimer's disease. In vitro also, the compound reduces the phosphorylation of Tau and inhibits the release of Aß peptides while preserving the processing of other metabolites of the amyloid precursor protein. We synthetized and tested the first drug capable of ameliorating both the amyloid and Tau pathology in animal models of AD as well as preventing the major brain lesions and associated memory impairments. This work paves the way for future compound medicines against both Alzheimer's-related brain lesions development and the associated cognitive impairments.

Exploring isoxazoles and pyrrolidinones decorated with the 4,6-dimethoxy-1,3,5-triazine unit as human farnesyltransferase inhibitors.

Unprecedented triazinyl-isoxazoles were afforded via an effective cycloaddition reaction between nitrile oxides and the scarcely described 2-ethynyl-4,6-dimethoxy-1,3,5-triazine as dipolarophile. The biological evaluation of the newly synthesized compounds showed that the inhibition of human farnesyltransferase by zinc complexation could be improved with triazine-isoxazole moieties. The replacement of the isoxazole unit by a pyrrolidin-2-one was detrimental to the inhibitory activity while the pyrrolidin-2-thione derivatives conserved the biological potential. The potential of selected compounds to disrupt protein farnesylation in Chinese hamster ovary (CHO) cells transfected with pEGFP-CAAX was also evaluated.

In vitro and in silico hormonal activity studies of di-(2-ethylhexyl)terephthalate, a di-(2-ethylhexyl)phthalate substitute used in medical devices, and its metabolites.

Plasticizers added to polyvinylchloride used in medical devices can be released into patients' biological fluids. The substitution of di-(2-ethylhexyl)phthalate (DEHP) by alternative plasticizers is essential but their safety must be demonstrated. DEHP, di-(2-ethylhexyl)terephthalate (DEHT) and their metabolites were investigated using level 2 Organization for Economic Co-operation and Development bioassays to screen for in vitro hormonal changes. Differences between the DEHP and DEHT metabolites were observed. Albeit weak, the hormonal activities of DEHT-derived metabolites, e.g., 5-OH metabolite of mono-(ethylhexyl)terephthalate (5-OH-MEHT), were detected and the results of docking experiments performed on estrogen receptor alpha and androgen receptor agreed with the biological results. A co-stimulation of human estrogen receptor alpha and human androgen receptor was also observed. With regard to steroidogenesis, a 16-fold increase in estrogen synthesis was measured with 5-OH-MEHT. Therefore, even if DEHT remains an interesting alternative to DEHP because of its low migration from medical devices, it seems important to verify that multi-exposed patients in neonatal intensive care units do not have urinary levels of oxidized metabolites, in particular 5-OH-MEHT, suggesting a potential endocrine-disrupting effect.

Chlorinated and brominated bisphenol A derivatives: Synthesis, characterization and determination in water samples.

Bisphenol A (BPA) has been used in the plastics industry for several decades. During the treatment of drinking water with chlorine reagent, the formation of chlorinated derivatives of BPA (ClxBPA) but also bromoBPA and bromochloroBPA is to be expected. Some of these compounds are considered to have an estrogenic effect and could induce major risks for human health by targeting different organs and systems in the body. In this paper, we describe the synthesis of chloro- and bromobisphenol A (ClxBPA, BrxBPA, BrxClxBPA)and their analytical characterization. These derivatives could be used as analytical standards in LC-MS/MS or evaluated in in vitro biological tests for their potential as endocrine disruptors. In this study, we evaluated the presence of BPA, ClxBPA in a pilot study from water samples. Range values found for BPA, ClxBPA were respectively 2.8-4169.3 ng/L and 0.8-11.3 ng/L.

Toward the Discovery of a Novel Class of YAP⁻TEAD Interaction Inhibitors by Virtual Screening Approach Targeting YAP⁻TEAD Protein⁻Protein Interface.

Intrinsically disordered protein YAP (yes-associated protein) interacts with TEADs transcriptional factors family (transcriptional enhancer associated domain) creating three interfaces. Interface 3, between the Ω-loop of YAP and a shallow pocket of TEAD was identified as the most important TEAD zone for YAP-TEAD interaction. Using the first X-ray structure of the hYAP50⁻71-hTEAD1209⁻426 complex (PDB 3KYS) published in 2010, a protein-protein interaction inhibitors-enriched library (175,000 chemical compounds) was screened against this hydrophobic pocket of TEAD. Four different chemical families have been identified and evaluated using biophysical techniques (thermal shift assay, microscale thermophoresis) and in cellulo assays (luciferase activity in transfected HEK293 cells, RTqPCR in MDA-MB231 cells). A first promising hit with micromolar inhibition in the luciferase gene reporter assay was discovered. This hit also decreased mRNA levels of TEAD target genes.

Synthesis and biological evaluation of ferrocene-based cannabinoid receptor 2 ligands.

Ferrocene analogs of known fatty acid amide hydrolase inhibitors and CB2 ligands have been synthesized and characterized spectroscopically and crystallographically. The resulting bio-organometallic isoxazoles were assayed for their effects on CB1 and CB2 receptors as well as on fatty acid amide hydrolase. None had any fatty acid amide hydrolase activity but compound 3, 5-(2-(pentyloxy)phenyl)-N-ferrocenylisoxazole-3-carboxamide, was found to be a potent CB2 ligand (Ki = 32.5 nM).

On the discovery of new potent human farnesyltransferase inhibitors: emerging pyroglutamic derivatives.

In the current context of lack of emergence of innovative human farnesyltransferase inhibitors families, and given all new therapeutic perspectives that open up for such molecules in rare diseases (e.g. Hutchinson-Gilford progeria syndrome), and in delta hepatitis, cardiovascular or neuroinflammatory diseases, we have just discovered a new series of powerful inhibitors. These molecules are pyroglutamic acid derivatives, and were evaluated on human farnesyltransferase in vitro then modeled in silico on the active site of the protein. Three main points of the pyroglutamic acid cycle have undergone chemical modulations pyroglutamides in position 5 (compounds 7a-h), constrained bicyclic analogues of pyrroloimidazoledione type (compounds 1a-h), modulation of the position 3 (compounds 2-5 and 8), and allowed the first SAR in the field. Five derivatives in the current work have IC50 values in the small nanomolar range (2-5 nM). These new lead compounds open the way for the next generation of farnesyltransferase inhibitors.

Anti-diabetic activity of fused PPARγ-SIRT1 ligands with limited body-weight gain by mimicking calorie restriction and decreasing SGK1 expression.

A series of benzothiazol-2-one containing α-ethoxyphenylpropionic acid derivatives incorporating resveratrol or butein scaffolds were designed as fused full PPARγ agonist ligands and SIRT1-activating compounds for the treatment of type 2 diabetes (T2D) and its complications. Compound 14d displayed the best in vitro pharmacological profile with full PPARγ agonist activity (Emax = 98%, EC50 = 200 nM), SIRT1 enzymatic activation (+128%) and SGK1 expression inhibition (- 57%) which is known to limit side effects as fluid retention and body-weight gain. Compound 14d showed high efficacy in an ob/ob mice model with significant decreases in serum triglyceride, glucose and insulin levels but mostly with limited body-weight gain by mimicking calorie restriction (CR) and inhibiting SGK1 expression.