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Background: Ganaplacide, also known as KAF156, is among the new antimalarial drug candidates that have successfully reached Phase III clinical trials, and is proposed in combination with lumefantrine. This combination could replace the current front-line artemisinin-based combination therapies (ACTs) in case of Plasmodium falciparum resistance to both artemisinins and partner drugs. Indeed, the African continent, where the malaria burden is the highest, is currently experiencing worrying multiple emergences and spread of artemisinin resistance, which urges for the exploration of the antiparasitic properties of KAF156 in this context., Objectives and Methods: The objectives of this work were firstly to evaluate the risk of cross-resistance between artemisinins and KAF156 alone, and in combination with lumefantrine, using a panel of artemisinin-resistant strains carrying different pfk13 mutations and markers of other antiplasmodial drug resistances; secondly to explore in vitro the relevance of combining KAF156 and lumefantrine with artemisinins, based on the model of triple ACTs., Results: Our results highlighted that KAF156 activity was not impaired by mutations in pfk13, pfcrt, pfmdr1, pfmdr2, pfdhps and pfdhfr genes or by pfmdr1 amplification. Moreover, we demonstrated that KAF156 alone and in combination with lumefantrine was active against artemisinin-resistant parasites, including when they are quiescent., Conclusions: All these in vitro results evidence that multi-drug resistant parasites currently in circulation in the field might not affect KAF156 efficacy, and are encouraging signs for KAF156 use in a triple ACT to preserve the use of artemisinins for as long as possible., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy.)

Direct-acting antivirals ledipasvir (LDV) and daclatasvir (DCV) are widely used as part of combination therapies to treat Hepatitis C infections. Here we show that these compounds inhibit the proliferation, invasion, and colony formation of triple-negative MDA-MB-231 breast cancer cells, SRC-transduced SW620 colon cancer cells and SRC- transduced NIH3T3 fibroblasts. DCV also inhibits the expression of PDL-1, which is responsible for resistance to immunotherapy in breast cancer cells. The demonstrated low toxicity in many Hepatitis C patients suggests LDV and DCV could be used in combination therapies for cancer patients. At the molecular level, these direct-acting antivirals inhibit the phosphorylation of Akt and the ephrin type A receptor 2 (EPHA2) by destabilizing a Src-EPHA2 complex, although they do not affect the general kinase activity of Src. Thus, LDV and DCV could be effective drugs for Src-associated cancers without the inherent toxicity of classical Src inhibitors., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Activation of pyruvate dehydrogenase (PDH) by inhibition of pyruvate dehydrogenase kinase (PDHK) has the potential for the treatment of diabetes mellitus and its complications, caused by the malfunction of the glycolytic system and glucose oxidation. In this paper, we describe the identification of novel PDHK inhibitors with a fluorene structure. High-throughput screening using our in-house library provided compound 6 as a weak inhibitor that occupied the allosteric lipoyl group binding site in PDHK2. Structure-based drug design (SBDD) while addressing physicochemical properties succeeded in boosting inhibitory activity approximately 700-fold. Thus obtained compound 32 showed favorable pharmacokinetics profiles supported by high membrane permeability and metabolic stability, and exhibited activation of PDH in rat livers and a glucose lowering effect in Zucker fatty rats., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Multicomponent biomolecular self-assembly is fundamental for accomplishing complex functionalities of biosystems. Self-assembling peptides, amino acids, and their conjugates serve as a versatile platform for developing biomaterials. However, the co-assembly of multiple building blocks showing synergistic interplay between individual components and producing biomaterials with emergent functional attributes is much less explored. In this study, we have formulated minimalistic co-assembled hydrogels composed of Fmoc-phenylalanine and Fmoc-lysine. The co-assembled systems display broad-spectrum antimicrobial potency, a feature absent in individual building blocks. A comprehensive biophysical analysis demonstrates the physicochemical features of the hydrogels eliciting the antibacterial response. MD simulation further reveals a unique fibrillar architecture with Fmoc-phenylalanine forming the fibril core surrounded by positively charged Fmoc-lysine surface residues, thereby enhancing the interaction with negatively charged bacterial membranes, causing membrane disruption and cell death. Thus, this study provides molecular-level insight into the emergent properties of a multicomponent system, affording an excellent paradigm for developing novel biomaterials.

Resistance-associated substitutions (RASs) of hepatitis C virus (HCV) affect the efficacy of direct-acting antivirals (DAAs). In this study, we aimed to clarify the susceptibility of the coexistence of nonstructural (NS) 5A Q24K/L28M/R30Q (or R30E)/A92K RASs, which were observed in patients with DAAs re-treatment failure and to consider new therapeutic agents. We used a subgenomic replicon system in which HCV genotype 1B strain 1B-4 was electroporated into OR6c cells derived from HuH-7 cells (Wild-type [WT]). We converted WT genes to NS5A Q24K/L28M/R30Q/A92K or Q24/L28K/R30E/A92K. Compared with the WT, the Q24K/L28M/R30Q/A92K RASs was 36,000-fold resistant to daclatasvir, 440,000-fold resistant to ledipasvir, 6300-fold resistant to velpatasvir, 3100-fold resistant to elbasvir, and 1.8-fold resistant to pibrentasvir. Compared with the WT, the Q24K/L28M/R30E/A92K RASs was 640,000-fold resistant to daclatasvir and ledipasvir, 150,000-fold resistant to velpatasvir, 44,000-fold resistant to elbasvir, and 1500-fold resistant to pibrentasvir. The Q24K/L28M/R30E/A92K RASs was 816.3 times more resistant to pibrentasvir than the Q24K/L28M/R30Q/A92K RASs. Furthermore, a combination of pibrentasvir and sofosbuvir showed therapeutic efficacy against these RASs. Combination regimens may eradicate HCV with NS5A Q24K/L28M/R30E/A92K RASs., (© 2024. The Author(s).)

Background: Despite efforts made to reduce morbidity and mortality associated with malaria, especially in sub-Saharan Africa, malaria continues to be a public health concern that requires innovative efforts to reach the WHO-set zero malaria agenda. Among the innovations is the use of artemisinin-based combination therapy (ACT) that is effective against Plasmodium falciparum. Generic artemether-lumefantrine (AL) is used to treat uncomplicated malaria after appropriate diagnosis. AL is metabolized by the cytochrome P450 family of enzymes, such as CYP2B6, CYP3A4 and CYP3A5, which can be under pharmacogenetic influence. Pharmacogenetics affecting AL metabolism, significantly influence the overall anti-malarial activity leading to variable therapeutic efficacy. This study focused on generic AL drugs used in malarial treatment as prescribed at health facilities and evaluated pharmacogenomic influences on their efficacy., Methods: Patients who have been diagnosed with malaria and confirmed through RDT and microscopy were recruited in this study. Blood samples were taken on days 1, 2, 3 and 7 for parasite count and blood levels of lumefantrine, artemisinin, desbutyl-lumefantrine (DBL), and dihydroartemisinin (DHA), the active metabolites of lumefantrine and artemether, respectively, were analysed using established methods. Pharmacogene variation analysis was undertaken using iPLEX microarray and PCR-RFLP., Results: A total of 52 patients completed the study. Median parasite density from day 1 to 7 ranged from 0-2666/μL of blood, with days 3 and 7 recording 0 parasite density. Highest median plasma concentration for lumefantrine and desbutyl lumefantrine, which are the long-acting components of artemisinin-based combinations, was 4123.75 ng/mL and 35.87 ng/mL, respectively. Day 7 plasma lumefantrine concentration across all generic ACT brands was ≥ 200 ng/mL which potentially accounted for the parasitaemia profile observed. Monomorphism was observed for CYP3A4 variants, while there were observed variations in CYP2B6 and CYP3A5 alleles. Among the CYP3A5 genotypes, significant differences in genotypes and plasma concentration for DBL were seen on day 3 between 1/*1 versus *1/*6 (p = 0.002), *1/*3 versus *1/*6 (p = 0.006) and *1/*7 versus *1/*6 (p = 0.008). Day 7 plasma DBL concentrations showed a significant difference between *1/*6 and *1/*3 (p = 0.026) expressors., Conclusions: The study findings show that CYP2B6 and CYP3A5 pharmacogenetic variations may lead to higher plasma exposure of AL metabolites., (© 2024. The Author(s).)

Eight new decahydrofluorene-class alkaloids, microascones A and B ( 1 and 2 ), 2,3-epoxyphomapyrrolidone C ( 3 ), 14,16-epiascomylactam B ( 4 ), 24-hydroxyphomapyrrolidone A ( 5 ), and microascones C-E ( 6 - 8 ), along with five known analogs ( 9 - 13 ) were isolated from the marine-derived fungus Microascus sp. SCSIO 41821. Compounds 1 and 2 have an unprecedented complex macrocyclic alkaloid skeleton with a 6/5/6/5/6/5/13 polycyclic system. Their structures and absolute configurations were determined by spectroscopic analysis, quantum chemical calculations of ECD spectra, and 13 C NMR chemical shifts. Compounds 10 - 13 showed selective enzyme inhibitory activity against PTPSig, PTP1B, and CDC25B, and 4 , 9 , and 10 exhibited strong antibacterial activity against seven tested pathogens. Their structure-bioactivity relationship was discussed, and a plausible biosynthetic pathway for 1 - 8 was also proposed.

Fluorene-9-bisphenol (BHPF) is an emerging global endocrine-disrupting chemical found in numerous household products as a substitute of bisphenol A. Many studies have reported various toxicities associated with BHPF. However, the effect of BHPF on male reproduction, particularly on the structural integrity of the blood testis barrier (BTB) in mice, has not yet been extensively studied. Ferroptosis, a newly identified form of cell death, occurs in the testicular tissue following exposure to BPA, affecting male fertility. We investigated whether ferroptosis plays a role in BHPF-induced testicular damage. The findings indicated that BHPF exposure led decreases in serum testosterone (T) concentration and sperm concentration and motility in mice. Furthermore, BHPF disrupted the BTB by interfering with key BTB-related proteins, including Cx43, β-catenin, and ZO-1. Moreover, BHPF induced ferroptosis through the induction of lipid peroxidation, iron overload, oxidative stress, and mitochondrial dysfunction in the testicular tissue. Inhibition of ferroptosis using Fer-1 mitigated the BHPF-induced damage to the BTB and ferroptosis in TM4 cells. Overall, our findings indicated the detrimental effects of BHPF on male reproductive function in mice, suggesting ferroptosis as a mechanism underlying testicular damage., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Fluorene was previously reported to have anticancer activity against human cancer cells. In this study, we examined the in vitro function of 9-methanesulfonylmethylene-2, 3-dimethoxy-9 H -fluorene (MSDF), a novel fluorene derivative, its anticancer potential in human hepatocellular carcinoma (HCC) cells and its underlying molecular mechanism. The disruption of cellular homeostasis caused by MSDF was found to promote reactive oxygen species (ROS) generation, leading to the activation of cellular apoptosis. As a survival strategy, cells undergo autophagy during oxidative stress. MSDF-induced apoptosis occurred through both receptor-mediated extrinsic and mitochondrial-mediated intrinsic routes. The development of acidic vesicular organelles and the accumulation of LC3-II protein suggest an increase in the autophagic process. Apoptosis was detected by double staining. The MAPK/ERK and PI3K/Akt signaling pathways were indeed suppressed during treatment. Along with elevated ROS generation and apoptosis, MSDF also caused anoikis and cell death by causing cells to lose contact with their extracellular matrix. ROS production was induced by MSDF and sustained by an NAC scavenger. MSDF-induced apoptosis led to increased autophagy, as shown by the suppression of apoptosis by Z-VAD-FMK. However, inhibition of autophagy by inhibitor 3-MA increased MSDF-induced apoptosis. More evidence shows that MSDF downregulated the expression of immune checkpoint proteins, suggesting that MSDF could be used in the future as an adjuvant to improve the effectiveness of HCC immunotherapy. Altogether, our results highlight the potential of MSDF as a multitarget drug for the treatment of HCC., Competing Interests: Declaration of competing interest We declare no conflict of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Emergence of drug resistance demands novel antimalarial drugs with new mechanisms of action. We aimed to identify effective and well tolerated doses of ganaplacide plus lumefantrine solid dispersion formulation (SDF) in patients with uncomplicated Plasmodium falciparum malaria., Methods: This open-label, multicentre, parallel-group, randomised, controlled, phase 2 trial was conducted at 13 research clinics and general hospitals in ten African and Asian countries. Patients had microscopically-confirmed uncomplicated P falciparum malaria (>1000 and <150 000 parasites per μL). Part A identified the optimal dose regimens in adults and adolescents (aged ≥12 years) and in part B, the selected doses were assessed in children (≥2 years and <12 years). In part A, patients were randomly assigned to one of seven groups (once a day ganaplacide 400 mg plus lumefantrine-SDF 960 mg for 1, 2, or 3 days; ganaplacide 800 mg plus lumefantrine-SDF 960 mg as a single dose; once a day ganaplacide 200 mg plus lumefantrine-SDF 480 mg for 3 days; once a day ganaplacide 400 mg plus lumefantrine-SDF 480 mg for 3 days; or twice a day artemether plus lumefantrine for 3 days [control]), with stratification by country (2:2:2:2:2:2:1) using randomisation blocks of 13. In part B, patients were randomly assigned to one of four groups (once a day ganaplacide 400 mg plus lumefantrine-SDF 960 mg for 1, 2, or 3 days, or twice a day artemether plus lumefantrine for 3 days) with stratification by country and age (2 to <6 years and 6 to <12 years; 2:2:2:1) using randomisation blocks of seven. The primary efficacy endpoint was PCR-corrected adequate clinical and parasitological response at day 29, analysed in the per protocol set. The null hypothesis was that the response was 80% or lower, rejected when the lower limit of two-sided 95% CI was higher than 80%. This study is registered with EudraCT (2020-003284-25) and ClinicalTrials.gov (NCT03167242)., Findings: Between Aug 2, 2017, and May 17, 2021, 1220 patients were screened and of those, 12 were included in the run-in cohort, 337 in part A, and 175 in part B. In part A, 337 adult or adolescent patients were randomly assigned, 326 completed the study, and 305 were included in the per protocol set. The lower limit of the 95% CI for PCR-corrected adequate clinical and parasitological response on day 29 was more than 80% for all treatment regimens in part A (46 of 50 patients [92%, 95% CI 81-98] with 1 day, 47 of 48 [98%, 89-100] with 2 days, and 42 of 43 [98%, 88-100] with 3 days of ganaplacide 400 mg plus lumefantrine-SDF 960 mg; 45 of 48 [94%, 83-99] with ganaplacide 800 mg plus lumefantrine-SDF 960 mg for 1 day; 47 of 47 [100%, 93-100] with ganaplacide 200 mg plus lumefantrine-SDF 480 mg for 3 days; 44 of 44 [100%, 92-100] with ganaplacide 400 mg plus lumefantrine-SDF 480 mg for 3 days; and 25 of 25 [100%, 86-100] with artemether plus lumefantrine). In part B, 351 children were screened, 175 randomly assigned (ganaplacide 400 mg plus lumefantrine-SDF 960 mg once a day for 1, 2, or 3 days), and 171 completed the study. Only the 3-day regimen met the prespecified primary endpoint in paediatric patients (38 of 40 patients [95%, 95% CI 83-99] vs 21 of 22 [96%, 77-100] with artemether plus lumefantrine). The most common adverse events were headache (in seven [14%] of 51 to 15 [28%] of 54 in the ganaplacide plus lumefantrine-SDF groups and five [19%] of 27 in the artemether plus lumefantrine group) in part A, and malaria (in 12 [27%] of 45 to 23 [44%] of 52 in the ganaplacide plus lumefantrine-SDF groups and 12 [50%] of 24 in the artemether plus lumefantrine group) in part B. No patients died during the study., Interpretation: Ganaplacide plus lumefantrine-SDF was effective and well tolerated in patients, especially adults and adolescents, with uncomplicated P falciparum malaria. Ganaplacide 400 mg plus lumefantrine-SDF 960 mg once daily for 3 days was identified as the optimal treatment regimen for adults, adolescents, and children. This combination is being evaluated further in a phase 2 trial (NCT04546633)., Funding: Novartis and Medicines for Malaria Venture., Competing Interests: Declaration of interests CW, KC, ID, RP, HC, and DM are employees of Novartis. GS and CR are employees and stockholders of Novartis. ACM and MEG are employees of Medicines for Malaria Venture. MPG received fees from Novartis for advisory work related to malaria. All other authors declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Exposure to phenols, phthalates, pesticides, and polycyclic aromatic hydrocarbons (PAHs) can harm the skeleton. However, data about the joint effects of these chemicals' mixture on bone health are limited. The final analysis involved 6766 participants aged over 20 years recruited from the National Health and Nutrition Examination Survey. Generalized linear regression, weighted quantile sum (WQS) regression, Bayesian kernel machine regression (BKMR), and quantile g-computation (qgcomp) were performed to investigate the association of the urinary levels of chemicals (three phenols, two chlorophenol pesticides, nine phthalates, and six polycyclic aromatic hydrocarbon [PAH] metabolites) with bone mineral density (BMD) measurements and osteoporosis (OP) risk. Generalized linear regression identified that benzophenone-3, 2,4-dichlorophenol, mono-n-butyl phthalate, 1-napthol, 3-fluorene, 2-fluorene, and 1-phenanthrene were significantly associated with lower BMD and increased OP risk. The WQS index was negatively associated with total femur, femoral neck, and lumbar spine vertebra 1 (L1) BMD among all the participants, with corresponding β (95% confidence interval) values of -0.028 g/cm 2 (-0.040, -0.017), -0.015 g/cm 2 (-0.025, -0.004), and -0.018 g/cm 2 (-0.033, -0.003). In the BKMR analysis, the overall effect of the mixture was significantly associated with femoral neck BMD among males and OP risk among females. The qgcomp model found a significant association between co-exposure and L1 BMD among all the participants and among males. Our study presents compelling epidemiological evidence that co-exposure to phenols, chlorophenol pesticides, phthalates, and PAHs is associated with reduced BMD and elevated OP risk. It provides epidemiologic evidence for the detrimental effects of these chemicals on bone health., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this overview the literature on benzo[ j ]fluoranthene-derived toxins produced by fungi is discussed with a view on isolation, structure, biological activities, biosynthesis, and total syntheses of the natural products. This class of compounds consists until now of 33 naturally occurring compounds, where 25 are chiral and eight contain no stereogenic centers. The relative configuration of xylarenol was clarified by comparison of experimental and calculated ECD spectra, and absolute configurations of four toxins were corrected. The compounds show various biological activities including antibiotic and cytotoxic properties.

Three new phenanthrene derivatives ( 1 , 2 , 4 ), one new fluorenone ( 3 ), and four known compounds ( 5 - 8 ) were isolated from the ethyl acetate extract of Dendrobium crumenatum Sw. stems using column chromatography. The chemical structures were elucidated by analysis of spectroscopic data. The absolute configuration of 4 was determined by electronic circular dichroism calculation. We also evaluated the immunomodulatory effects of compounds isolated from D. crumenatum in human peripheral blood mononuclear cells from healthy individuals and those from patients with multiple sclerosis in vitro. Dendrocrumenol B ( 2 ) and dendrocrumenol D ( 4 ) showed strong immunomodulatory effects on both CD3 + T cells and CD14 + monocytes. Compounds 2 and 4 could reduce IL-2 and TNF production in T cells and monocytes that were treated with phorbol-12-myristate-13-acetate and ionomycin (PMA/Iono). Deep immune profiling using high-dimensional single-cell mass cytometry could confirm immunomodulatory effects of 4 , quantified by the reduction of activated T cell population under PMA/Iono stimulation, in comparison to the stimulated T cells without treatment.

Macrocyclic alkaloids with a cyclopenta[b]fluorene ring system are a relatively young structural class of fungal metabolites, with the first members reported in 2013. Bioassay-guided fractionation of a Sarocladium sp. (fungal strain MSX6737) led to a series of both known and new members of this structural class ( 1 - 5 ), including the known embellicine A ( 1 ), three new embellicine analogues ( 2 , 4 , and 5 ), and a semisynthetic acetylated analogue ( 3 ). The structures were identified by examining both high-resolution electrospray ionization mass spectrometry data and one-dimensional and two-dimensional NMR spectra. The relative configurations of these molecules were established via 1 H- 1 H coupling constants and nuclear Overhauser effect spectroscopy, while comparisons of the experimental electronic circular dichroism (ECD) spectra with the time-dependent density functional theory ECD calculations were utilized to assign their absolute configurations, which were in good agreement with the literature. These alkaloids ( 1 - 5 ) showed cytotoxic activity against a human breast cancer cell line (MDA-MB-231) that ranged from 0.4 to 4.8 μM. Compounds 1 and 5 were also cytotoxic against human ovarian (OVCAR3) and melanoma (MDA-MB-435) cancer cell lines.

Background: The purpose of this study was to investigate the effects of polycyclic aromatic hydrocarbons (PAHs) other than bisphenol A (BPA) and BPA substitutes on placental cells., Methods: HTR-8/SVneo cells were treated with anthracene, benzo[k]fluoranthene, benzo[a]pyrene, and 4,4-(9-fluorenylidene)diphenol, which is used as a substitute for BPA-free products. After confirming the dose response for each reagent using the prepared cells, the cells were incubated for 24, 48, and 72 h. Cell viability was confirmed using the XTT assay. Each experiment was performed with the minimum number of samples (n = 3) required for statistical analysis. The results were analyzed using t-tests; p < 0.05 was considered statistically significant., Results: After treatment with anthracene, benzo[k]fluoranthene, benzo[a]pyrene, and 4,4-(9-fluorenylidene)diphenol, the absorbance measured using the XTT assay decreased significantly with increasing concentration. The absorbance decreased significantly over time following treatment with each endocrine disruptor at the concentration confirmed by the dose-response analysis., Conclusions: This study showed that anthracene, benzo[k]fluoranthene, benzo[a]pyrene, and 4,4-(9-fluorenylidene)diphenol-a BPA substitute-affect cell viability and necrosis in the placental cell line. The study indicates the serious effects of PAHs that negatively affect pregnancy but were previously unknown. Further, this study would serve as a reference for the identification of harmful PAHs during pregnancy prognosis in women who are more susceptible to PAH exposure., (© 2022. The Author(s).)

Despite recent improvements in treatment modalities, pancreatic cancer remains a highly lethal tumor with mortality rate increasing every year. Poly (ADP-ribose) polymerase (PARP) inhibitors are now used in pancreatic cancer as a breakthrough in targeted therapy. This study focused on whether PARP inhibitors (PARPis) can affect programmed death ligand-1 (PD-L1) expression in pancreatic cancer and whether immune checkpoint inhibitors of PD-L1/programmed death 1 (PD-1) can enhance the anti-tumor effects of PARPis. Here we found that PARPi, pamiparib, up-regulated PD-L1 expression on the surface of pancreatic cancer cells in vitro and in vivo . Mechanistically, pamiparib induced PD-L1 expression via JAK2/STAT3 pathway, at least partially, in pancreatic cancer. Importantly, pamiparib attenuated tumor growth; while co-administration of pamiparib with PD-L1 blockers significantly improved the therapeutic efficacy in vivo compared with monotherapy. Combination therapy resulted in an altered tumor immune microenvironment with a significant increase in windiness of CD8 + T cells, suggesting a potential role of CD8 + T cells in the combination therapy. Together, this study provides evidence for the clinical application of PARPis with anti-PD-L1/PD-1 drugs in the treatment of pancreatic cancer., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wang, Zheng, Xiong, Huang, Chen, Zhou, Qin, Su, Chen, Qiu, Yuan, Wang and Zou.)

The pandemic of SARS-CoV-2 has necessitated expedited research efforts towards finding potential antiviral targets and drug development measures. While new drug discovery is time consuming, drug repurposing has been a promising area for elaborate virtual screening and identification of existing FDA approved drugs that could possibly be used for targeting against functions of various proteins of SARS-CoV-2 virus. RNA dependent RNA polymerase (RdRp) is an important enzyme for the virus that mediates replication of the viral RNA. Inhibition of RdRp could inhibit viral RNA replication and thus new virus particle production. Here, we screened non-nucleoside antivirals and found three out of them to be strongest in binding to RdRp out of which two retained binding even using molecular dynamic simulations. We propose these two drugs as potential RdRp inhibitors which need further in-depth testing., Competing Interests: Declaration of competing interest Authors declare no conflicts of interest., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: Comorbid conditions of heart and liver disorders added to HCV-induced hepatic steatosis make co-administration of statins, and direct-acting antivirals is common in clinical practice. This study aimed to evaluate the pharmacokinetic interaction of atorvastatin and fixed-dose combination of sofosbuvir/ledipasvir "FDCSL" with rationalization to the underlying mechanism., Methods: A randomized, three-phase crossover study that involves 12 healthy volunteers was performed. Participants received a single-dose of atorvastatin 80 mg alone, atorvastatin 80-mg plus tablets containing 400/90 mg FDCSL, or tablets containing 400/90 mg FDCSL alone. Plasma samples were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for atorvastatin, sofosbuvir, ledipasvir, and sofosbuvir metabolite "GS-331007," and their pharmacokinetics parameters were determined., Results: Compared to atorvastatin alone, the administration of FDCSL caused a significant increase in both areas under the concentration-time curve from time zero to infinity (AUC 0-∞ ) and maximum plasma concentration (C max ) of atorvastatin by 65.5% and 156.0%, respectively. Also, atorvastatin caused a significant increase in the AUC 0-∞ and C max of sofosbuvir by 32.0% and 11.0%, respectively. Similarly, AUC 0-∞ and C max of sofosbuvir metabolite significantly increased by 84.0% and 74.0%, respectively. However, ledipasvir AUC 0-∞ showed no significant change after atorvastatin intake. The elimination rate in all drugs revealed no significant changes., Conclusion: After concurrent administration of FDCSL with atorvastatin, the AUC 0-∞ of both atorvastatin and sofosbuvir were increased. Caution should be taken with close monitoring for possible side effects after co-administration of atorvastatin and FDCSL in clinical practice., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this paper, we applied an innovative nuclear magnetic resonance (NMR)-guided screening and ligand design approach, named focused high-throughput screening by NMR (fHTS by NMR), to derive potent, low-molecular-weight ligands capable of mimicking interactions elicited by ephrin ligands on the receptor tyrosine kinase EphA4. The agents bind with nanomolar affinity, trigger receptor activation in cellular assays with motor neurons, and provide remarkable motor neuron protection from amyotrophic lateral sclerosis (ALS) patient-derived astrocytes. Structural studies on the complex between EphA4 ligand-binding domain and a most active agent provide insights into the mechanism of the agents at a molecular level. Together with preliminary in vivo pharmacology studies, the data form a strong foundation for the translation of these agents for the treatment of ALS and potentially other human diseases.

Fluorescent voltage indicators are an attractive alternative for studying the electrical activity of excitable cells; however, the development of indicators that are both highly sensitive and low in toxicity over long-term experiments remains a challenge. Previously, we reported a fluorene-based voltage-sensitive fluorophore that exhibits much lower phototoxicity than previous voltage indicators in cardiomyocyte monolayers, but suffers from low sensitivity to membrane potential changes. Here, we report that the addition of a single vinyl spacer in the fluorene molecular wire scaffold improves the voltage sensitivity 1.5- to 3.5-fold over fluorene-based voltage probes. Furthermore, we demonstrate the improved ability of the new vinyl-fluorene VoltageFluors to monitor action potential kinetics in both mammalian neurons and human-induced pluripotent stem cell-derived cardiomyocytes. Addition of the vinyl spacer between the aniline donor and fluorene monomer results in indicators that are significantly less phototoxic in cardiomyocyte monolayers. These results demonstrate how structural modification to the voltage sensing domain have a large effect on improving the overall properties of molecular wire-based voltage indicators.

To further pursue potent Bax activators with better safety profiles for the treatment of breast cancer, structural optimization was conducted based on lead compound CYD-4-61 through several strategies, including scaffold hopping on the 2-nitro-fluorene ring, replacement of the nitro group with bioisosteres to avoid potential toxicity, and further optimization on the upper pyridine by exploring diverse alkylamine linkers as a tail or replacing the pyridine with bioisosteric heterocycles. F-containing compound 22d (GL0388) exhibited a good balance between the activity and toxicity, displaying submicromolar activities against a variety of cancer cell lines with 5.8-10.7-fold selectivity of decreased activity to MCF-10A human mammary epithelial cell line. Compound 22d dose-dependently blocked colony formation of breast cancer cells and prevented the migration and invasion of MDA-MB-231 cells. Mechanism of action studies indicate that 22d activated Bax, rendering its insertion into mitochondrial membrane, thereby leading to cytochrome c release from the mitochondria into the cytoplasm, subsequently inducing release of apoptotic biomarkers. Further in vivo efficacy studies of 22d in human breast cancer xenografts arisen from MDA-MB-231 cells demonstrated that this drug candidate significantly suppressed tumor growth, indicating the therapeutic promise of this class of compounds for the treatment of breast cancer as well as the potential for developing F-radiolabeled imaging ligands as anticancer chemical probes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Pamiparib (PARTRUVIX™; BeiGene Ltd.) is a selective poly (ADP-ribose) polymerase 1 and 2 (PARP1 and PARP2) inhibitor being developed for the treatment of various cancers. Based on the results from the pivotal phase II portion of a phase I/II trial (NCT03333915) pamiparib was recently approved in China for the treatment of germline BRCA mutation-associated recurrent advanced ovarian, fallopian tube or primary peritoneal cancer previously treated with two or more lines of chemotherapy. This article summarizes the milestones in the development of pamiparib leading to this first approval., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Marine microorganisms have been a resource for novel therapeutic drugs for decades. In addition to anticancer drugs, the drug acyclovir, derived from a marine sponge, is FDA-approved for the treatment of human herpes simplex virus-1 infections. Most alphaviruses that are infectious to terrestrial animals and humans, such as Venezuelan and eastern equine encephalitis viruses (VEEV and EEEV), lack efficient antiviral drugs and it is imperative to develop these remedies. To push the discovery and development of anti-alphavirus compounds forward, this study aimed to isolate and screen for potential antiviral compounds from cultured marine microbes originating from the marine environment. Compounds from marine microbes were of interest as they are prolific producers of bioactive compounds across the spectrum of human diseases and infections. Homoseongomycin, an actinobacteria isolated from a marine sponge displayed impressive activity against VEEV from a total of 76 marine bioactive products. The 50% effective concentration (EC 50 ) for homoseongomycin was 8.6 μM for suppressing VEEV TC-83 luciferase reporter virus replication. Homoseongomycin was non-toxic up to 50 μM and partially rescued cells from VEEV induced cell death. Homoseongomycin exhibited highly efficient antiviral activity with a reduction of VEEV infectious titers by 8 log 10 at 50 μM. It also inhibited EEEV replication with an EC 50 of 1.2 μM. Mechanism of action studies suggest that homoseongomycin affects both early and late stages of the viral life cycle. Cells treated with 25 μM of homoseongomycin had a ~90% reduction in viral entry. In comparison, later stages showed a more robust reduction in infectious titers (6 log 10 ) and VEEV extracellular viral RNA levels (4 log 10 ), but a lesser impact on intracellular viral RNA levels (1.5 log 10 ). In sum, this work demonstrates that homoseongomycin is a potential anti-VEEV and anti-EEEV compound due to its low cytotoxicity and potent antiviral activity., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Antimicrobial resistance is one of the major public health threats at the global level, urging the search for new antimicrobial molecules. The fluorene nucleus is a component of different bioactive compounds, exhibiting diverse pharmacological actions. The present work describes the synthesis, chemical structure elucidation, and bioactivity of new O-aryl-carbamoyl-oxymino-fluorene derivatives and the contribution of iron oxide nanoparticles to enhance the desired biological activity. The antimicrobial activity assessed against three bacterial and fungal strains, in suspension and biofilm growth state, using a quantitative assay, revealed that the nature of substituents on the aryl moiety are determinant for both the spectrum and intensity of the inhibitory effect. The electron-withdrawing inductive effect of chlorine atoms enhanced the activity against planktonic and adhered Staphylococcus aureus , while the +I effect of the methyl group enhanced the anti-fungal activity against Candida albicans strain. The magnetite nanoparticles have substantially improved the antimicrobial activity of the new compounds against planktonic microorganisms. The obtained compounds, as well as the magnetic core@shell nanostructures loaded with these compounds have a promising potential for the development of novel antimicrobial strategies.

To investigate the suppressive function of RO4929097, a potent -secretase inhibitor, on RANKL-induced osteoclastogenesis. The cytotoxicity of RO4929097 was evaluated. The suppressive effect and possible molecular mechanism of RO4929097 on RANKL-induced osteoclastogenesis was evaluated both in vitro and in vivo . The IC50 of RO4929097 was 2.93 μM. Treatment with different doses of RO4929097 (100 nM, 200 nM, and 400 nM) effectively reduced osteoclast formation (number and resorption area) in a dose-dependent manner. The qPCR results revealed that RO4929097 attenuates RANKL-induced osteoclast formation and NFATc1 protein expression. The in vivo experiments demonstrated that RO4929097 had an inhibitory effect on LPS-induced bone resorption. Our in vitro experiments showed that RO4929097 can potently inhibit osteoclastogenesis and bone resorption by down-regulating the Notch/MAPK/JNK/Akt-mediated reduction of NFATc1. In accordance with these in vitro observations, RO4929097 attenuated LPS-induced osteolysis in mice. In conclusion, our findings indicate that Notch may represent a potential therapeutic target for the treatment of osteolytic diseases.

The rapid spread of the virus, the surge in the number of deaths, and the unavailability of specific SARS-CoV-2 drugs thus far necessitate the identification of drugs with anti-COVID-19 activity. SARS-CoV-2 enters the host cell and assembles a multisubunit RNA-dependent RNA polymerase (RdRp) complex of viral nonstructural proteins that plays a substantial role in the transcription and replication of the viral genome. Therefore, RdRp is among the most suitable targets in RNA viruses. Our aim was to investigate the FDA approved antiviral drugs having potential to inhibit the viral replication. The methodology adopted was virtual screening and docking of FDA-approved antiviral drugs into the RdRp protein. Top hits were selected and subjected to molecular dynamics simulations to understand the dynamics of RdRp in complex with these drugs. The antiviral activity of the drugs against SARS-CoV-2 was assessed in Vero E6 cells. Notably, both remdesivir (half-maximal effective concentration (EC50) 6.6 μM, 50% cytotoxicity concentration (CC 50 ) > 100 µM, selectivity index (SI) = 15) and ledipasvir (EC50 34.6 μM, CC 50 > 100 µM, SI > 2.9) exerted antiviral action. This study highlights the use of direct-acting antiviral drugs, alone or in combination, for better treatments of COVID-19.

(-)-Lomaiviticin A ( 1 ) is a genotoxic C 2 -symmetric metabolite that arises from the formal dimerization of two bis(glycosylated) diazotetrahydrobenzo[ b ]fluorenes. Here we present a synthesis of the monomer 17 and its coupling to form (2 S ,2' S )-lomaiviticin A ( 4 ), an unnatural diastereomer of 1 . (2 S ,2' S )-Lomaiviticin A ( 4 ) is significantly less genotoxic, a result we attribute to changes in the orientation of the diazofluorene and carbohydrate residues, relative to 1 . These data bring the importance of the configuration of the conjoining bond to light and place the total synthesis of 1 itself within reach.

We discovered that 2,7-diaminofluorene or 2,7-diaminocarbazole moiety can be employed as a core structure of highly effective NS5A inhibitors that are connected through amide bonds to proline-valine-carbamate motifs. Amide bonds can be easily cleaved via various metabolic pathways upon administration into the body, and metabolites containing 2,7-diaminofluorene and 2,7-diaminocarbazole core structures have been known to be strong mutagens. To avoid the mutagenesis issue of these core structures, we examined various functional groups at the C9 or N9 position of 2,7-diaminofluorene or 2,7-diaminocarbazole, respectively, through the Ames test in TA98 and TA100 mutants of Salmonella typhimurium LT-2. We discovered that, through proper alkyl substitution at the C9 or N9 position, 2,7-diaminofluorene and 2,7-diaminocarbazole moieties can be successfully employed in drug discovery without necessarily causing mutagenicity problems., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Poly (ADP-ribose) polymerase (PARP) plays a significant role in DNA repair responses; therefore, this enzyme is targeted by PARP inhibitors in cancer therapy. Here we have developed a number of fused tetra- or pentacyclic dihydrodiazepinoindolone derivatives with excellent PARP enzymatic and cellular PARylation inhibition activities. These efforts led to the identification of pamiparib (BGB-290, 139 ), which displays excellent PARP-1 and PARP-2 inhibition with IC 50 of 1.3 and 0.9 nM, respectively. In a cellular PARylation assay, this compound inhibits PARP activity with IC 50 = 0.2 nM. Cocrystal of pamiparib shows similar binding sites with PARP with other PARP inhibitors, but pamiparib is not a P-gp substrate and shows excellent drug metabolism and pharmacokinetics (DMPK) properties with significant brain penetration (17-19%, mice). The compound is currently being investigated in phase III clinical trials as a maintenance therapy in platinum-sensitive ovarian cancer and gastric cancer.

Alzheimer's disease (AD) is a complex disorder with unknown etiology. Currently, only symptomatic therapy of AD is available, comprising cholinesterase inhibitors and N -methyl-d-aspartate (NMDA) receptor antagonists. Drugs targeting only one pathological condition have generated only limited efficacy. Thus, combining two or more therapeutic interventions into one molecule is believed to provide higher benefit for the treatment of AD. In the presented study, we designed, synthesized, and biologically evaluated 15 novel fluoren-9-amine derivatives. The in silico prediction suggested both the oral availability and permeation through the blood-brain barrier (BBB). An initial assessment of the biological profile included determination of the cholinesterase inhibition and NMDA receptor antagonism at the GluN1/GluN2A and GluN1/GluN2B subunits, along with a low cytotoxicity profile in the CHO-K1 cell line. Interestingly, compounds revealed a selective butyrylcholinesterase (BChE) inhibition pattern with antagonistic activity on the NMDARs. Their interaction with butyrylcholinesterase was elucidated by studying enzyme kinetics for compound 3c in tandem with the in silico docking simulation. The docking study showed the interaction of the tricyclic core of new derivatives with Trp82 within the anionic site of the enzyme in a similar way as the template drug tacrine. From the kinetic analysis, it is apparent that 3c is a competitive inhibitor of BChE.

The World Health Organisation's goal of hepatitis C virus (HCV) elimination by 2030 will require lower drug prices. Estimates of comparative efficacy promote competition between pharmaceutical companies but direct acting antivirals have been approved for the treatment of HCV without comparative trials. We emulated a randomized trial to answer the question of whether easy to treat patients with genotype 1 HCV could be treated with sofosbuvir/ledipasvir (SOF/LDV) rather than sofosbuvir/velpatasvir (SOF/VEL). Patients without comorbidities or end stage liver disease were selected from the British Colombia Hepatitis Testers Cohort. To create a conceptual trial, we matched each patient starting SOF/VEL (a 'case') to the patient starting SOF/LDV with the closest propensity score (a 'control'). We estimated the probability of treatment failure under a Bayesian logistic model with a random effect for each case-control set and used that model to give an estimate of a risk difference for the conceptual trial. Treatment failure was recorded for 27 of 825 (3%) cases and for 29 of 602 (5%) matched controls. Estimates from our model were treatment success rates of 97% (95% credible interval, CrI, 95%-98%) for treatment with SOF/VEL, 95% (95% CrI 93%-97%) for treatment with SOF/LDV and a risk difference between treatments of 2% (95% CrI 0%-4%). This risk difference is evidence that SOF/LDV is not inferior to SOF/VEL for easy to treat patients with genotype 1 HCV. The approach is a template for comparing drugs when there are no data from comparative trials., (© 2020 The Authors. Pharmacology Research & Perspectives published by British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics and John Wiley & Sons Ltd.)

Background & Aims: The efficacy of NS5A inhibitors against several less common subtypes of hepatitis C virus (HCV) is poorly characterised. Some subtypes including 3b, 3g, 6u and 6v commonly harbour amino acid residues in NS5A that may confer resistance to direct-acting antivirals (DAAs) in other common subtypes. Data from patients also suggest that 1l and 4r with amino acid substitutions at positions 28-31 and 93 in NS5A are relatively resistant to DAA therapy., Methods: In this study, we tested the efficacy of daclatasvir, elbasvir, ledipasvir, pibrentasvir and velpatasvir against these subtypes using the SGR-JFH1 replicon backbone., Results: NS5A inhibitors showed different levels of efficacy with only pibrentasvir effective against all tested subtypes. Daclatasvir and ledipasvir were ineffective against 6u and 6v (half maximal effective concentration [EC 50 ] values of 239-321 nM) while 3b and 3g were only susceptible to pibrentasvir. Analysis of effects of individual mutations indicated that Q30R in 1l increased the EC 50 of ledipasvir by 18-fold, conferring intermediate resistance, while those of L31M and Y93H in 4r induced increases in EC 50 values of 2,100- and 3,575-fold (high-level resistance)., Conclusion: The high ledipasvir EC 50 values of 1l with the Q30R substitution, 4r L31M and 4r Y93H may explain the treatment failure in patients who were infected with these viruses and treated with ledipasvir + sofosbuvir. This study also shows the ineffectiveness of the first generation NS5A inhibitors against 6u and 6v, and confirms the inherent resistance of 3b and 3g to most NS5A inhibitors. Clinical studies to confirm in vivo sensitivity to NS5A inhibitors are urgently needed so that rational, effective treatment strategies may be developed for unusual subtypes., Lay Summary: Little is known about the efficacy of NS5A inhibitors against some "unusual" hepatitis C virus (HCV) subtypes including 1l, 3b, 3g, 4r, 6u and 6v. In this study, we manufactured HCV replicons which express the NS5A protein from the unusual HCV subtypes 1l, 3b, 3g, 4r, 6u, 6v. We then tested the effect of the NS5A inhibitors daclatasvir, elbasvir, ledipasvir, pibrentasvir and velpatasvir on blocking replication, using these replicons. We show that these replicons are resistant at some level to all NS5A inhibitors other than pibrentasvir., Competing Interests: Conflict of interest The authors declare no conflicts of interest that pertain to this work. Please refer to the accompanying ICMJE disclosure forms for further details., (Copyright © 2020. Published by Elsevier B.V.)

Here we report bisphenol derivatives of fluorene (BDFs) as a new type of chemical probes targeting a histone-like HU protein, a global regulator of bacterial nucleoids, via its dimerization interface perturbation. BDFs were identified by virtual screening and molecular docking that targeted the core of DNA-binding β-saddle-like domain of the HU protein from Spiroplasma melliferum. However, NMR spectroscopy, complemented with molecular dynamics and site-directed mutagenesis, indicated that the actual site of the inhibitors' intervention consists of residues from the α-helical domain of one monomer and the side portion of the DNA-binding domain of another monomer. BDFs inhibited DNA-binding properties of HU proteins from mycoplasmas S. melliferum, Mycoplasma gallicepticum and Escherichia coli with half-maximum inhibitory concentrations in the range between 5 and 10 µM. In addition, BDFs demonstrated antimicrobial activity against mycoplasma species, but not against E. coli, which is consistent with the compensatory role of other nucleoid-associated proteins in the higher bacteria. Further evaluation of antimicrobial effects of BDFs against various bacteria and viruses will reveal their pharmacological potential, and the allosteric inhibition mode reported here, which avoids direct competition for the binding site with DNA, should be considered in the development of small molecule inhibitors of nucleoid-associated proteins as well as other types of DNA-binding multimeric proteins.

Pamiparib, an investigational Poly (ADP-ribose) polymerase (PARP) inhibitor in clinical development, demonstrates excellent selectivity for both PARP1 and PARP2, and superb anti-proliferation activities in tumor cell lines with BRCA1/2 mutations or HR pathway deficiency (HRD). Pamiparib has good bioavailability and is 16-fold more potent than olaparib in an efficacy study using BRCA1 mutated MDA-MB-436 breast cancer xenograft model. Pamiparib also shows strong anti-tumor synergy with temozolomide (TMZ), a DNA alkylating agent used to treat brain tumors. Compared to other PARP inhibitors, pamiparib demonstrated improved penetration across the blood brain barrier (BBB) in mice. Oral administration of pamiparib at a dose as low as 3 mg/kg is sufficient to abrogate PARylation in brain tumor tissues. In SCLC-derived, TMZ-resistant H209 intracranial xenograft model, combination of pamiparib with TMZ overcomes its resistance and shows significant tumor inhibitory effects and prolonged life span. Our data suggests that combination of pamiparib with TMZ has unique potential for treatment of brain tumors. Currently, the combination therapy of pamiparib with TMZ is evaluated in clinical trial [NCT03150862]., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

We prepared the three-dimensional model of the SARS-CoV-2 (aka 2019-nCoV) 3C-like protease (3CL pro ) using the crystal structure of the highly similar (96% identity) ortholog from the SARS-CoV. All residues involved in the catalysis, substrate binding and dimerisation are 100% conserved. Comparison of the polyprotein PP1AB sequences showed 86% identity. The 3C-like cleavage sites on the coronaviral polyproteins are highly conserved. Based on the near-identical substrate specificities and high sequence identities, we are of the opinion that some of the previous progress of specific inhibitors development for the SARS-CoV enzyme can be conferred on its SARS-CoV-2 counterpart.  With the 3CL pro molecular model, we performed virtual screening for purchasable drugs and proposed 16 candidates for consideration. Among these, the antivirals ledipasvir or velpatasvir are particularly attractive as therapeutics to combat the new coronavirus with minimal side effects, commonly fatigue and headache.  The drugs Epclusa (velpatasvir/sofosbuvir) and Harvoni (ledipasvir/sofosbuvir) could be very effective owing to their dual inhibitory actions on two viral enzymes., Competing Interests: No competing interests were disclosed., (Copyright: © 2020 Chen YW et al.)

Approximately 71 million people suffer from hepatitis C virus (HCV) infection worldwide. Persistent HCV infection causes liver diseases such as chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma, resulting in approximately 400,000 deaths annually. Effective direct-acting antiviral agents (DAAs) have been developed and are currently used for HCV treatment targeting the following three proteins: NS3/4A proteinase that cleaves the HCV polyprotein into various functional proteins, RNA-dependent RNA polymerase (designated as NS5B), and NS5A, which is required for the formation of double membrane vesicles serving as RNA replication organelles. At least one compound inhibiting NS5A is included in current HCV treatment regimens due to the high efficacy and low toxicity of drugs targeting NS5A. Here we report fluorene compounds showing strong inhibitory effects on GT 1b and 3a of HCV. Moreover, some compounds were effective against resistance-associated variants to DAAs. The structure-activity relationships of the compounds were analyzed. Furthermore, we investigated the molecular bases of the inhibitory activities of some compounds by the molecular docking method., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Microplastic particles (MPs) from lipophilic polymers have been shown to efficiently accumulate hydrophobic organic contaminants (HOCs) in aquatic environments. MPs have, therefore, frequently been discussed as vectors for contaminants, enhancing HOC uptake by various organisms after ingestion followed by pollutant release; however, integrative models of sorption argue against this mechanism and even predict cleansing of pollutants from biological systems under particular circumstances. In order to experimentally investigate such a depuration mechanism, RTL-W1 cells were dosed with three 7-ethoxyresorufin-O-deethylase (EROD) inducers of distinct lipophilicity via the medium before adding both native and hexane-purified polyethylene MPs (20-25 μm) to the medium surface. EROD activity was significantly reduced in the presence of MP, the extent of which correlated with the inducers' lipophilicity (K OW ) and thus affinity to MP. For hexane-purged MPs and TCDD (K OW  = 6.8), MPs reduce the bioavailability by up to 79%; the effect was marginally weaker with benzo[k]fluoranthene (K OW  = 6.11) and almost absent with β-Naphthoflavone (K OW  = 4.68). Compared to hexane-purged MPs, native particles possessed slightly less detoxification potential. These experimental results corroborate theoretically predicted mechanisms of detoxification via MPs. Yet, it is unclear if, under corresponding conditions in the environment, MPs can compete with organismal tissues for highly lipophilic compounds and, if so, to which degree they may act as a sink reducing the amount of bioavailable pollutants in situ. However, the present results suggest that in scenarios where pollutant-free MPs interact with organisms that accumulated HOCs via other routes of uptake, qualitatively the presence of such a mechanism is likely., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Cholangiocarcinoma (CCA) mortality rates are increasing as a result of rising incidence and limited curative treatment(s) for patients with advanced disease. NOTCH pathway reactivation has been reported in biliary malignancies to conflicting degrees, hindering prioritization of key therapeutic targets within the network and identification of candidate responder patients for NOTCH-directed therapies. We analyzed genomic data from 341 patients with CCA and identified NOTCH1 significantly increased in a subgroup characterized by distinct stromal infiltration. Network-wide imbalance of the NOTCH pathway was seen in CCA, including correlation of NOTCH1 with NOTCH3 and NOTCH ligands. Given the diversity of observed NOTCH receptor engagement, γ-secretase modulation was rationalized as a therapeutic option. Indeed, subcutaneous transplantation of sensitive and resistant CCA cell lines pretreated with a γ-secretase inhibitor (GSi) cocktail demonstrated the antineoplastic effects of GSi in a subset of CCA and led to the development of a 225-gene responder signature. This signature was validated in an independent cohort of 119 patients. Further, this signature was enriched in liver tumors initiated by hydrodynamic injections of activated-NOTCH as compared with the AKT-RAS-driven tumors. Candidate GSi-responder patients were characterized by distinct transcriptomes overlapping with previous hepatobiliary metastasis and stemness, unique stromal properties, and dysfunctional intratumoral immune infiltration. Pan-cancer analysis identified 41.9% of cancer types to harbor prospective GSi-responder patients, which was adapted into a 20-gene GSi-sensitivity score metric capable of discriminating nanomolar versus micromolar sensitivity to a cell-permeable GSi (Z-LLNle-CHO) across 60 diverse tumor lines (area under the curve = 1). Conclusion: We have established a GSi-responder signature with evidence across several patient cohorts, as well as in vitro and in vivo models, to enable precision medicine application of NOTCH-directed therapy in CCA as well as prospectively across diverse malignancies., (© 2019 by the American Association for the Study of Liver Diseases.)

Borylated poly(fluorene-benzothiadiazoles) (PF8-BT) are π-conjugated polymers (CPs) with deep-red/ near-infrared (NIR) absorption and emission profiles suitable for in vivo optical imaging. A fully borylated PF8-BT derivative (P4) was encapsulated in pegylated poly(lactic- co -glycolic acid) (PEG-PLGA) nanoparticles and compared with a reference NIR-emitting CP (PCPDTBT) or indocyanine green (ICG). All formulations satisfied quality requirements for parenterally administered diagnostics. P4 nanoparticles had higher quantum yield (2.3%) than PCPCDTBT (0.01%) or ICG nanoparticles (1.1%). The signal/background ratios (SBRs) of CP systems P4 and PCPDTBT in a phantom mouse (λ em = 820 nm) increased linearly with fluorophore mass (12.5-100 μg/mL), while the SBRs of ICG decreased above 25 μg/mL. P4 nanoparticles experienced <10% photobleaching over 10 irradiations (PCPDTBT: ∼25% and ICG: >44%). In a mouse tumor xenograft model, P4 nanoparticles showed a 5-fold higher SBR than PCPDTBT particles with fluorophore accumulation in the liver > spleen > tumor. Blood chemistry and tissue histology showed no abnormalities compared to untreated animals after a single administration.

Background & Aims: HCV subtypes which are unusual in Europe are more prevalent in the African region, but little is known of their response to direct-acting antivirals (DAAs). These include non-1a/1b/ non-subtypeable genotype 1 (G1) or non-4a/4d (G4). In this report we aimed to describe the genotype distribution and treatment outcome in a south London cohort of African patients., Methods: We identified all patients born in Africa who attended our clinic from 2010-2018. Information on HCV genotype, treatment regimen and outcome were obtained. Non-subtypeable samples were analysed using Glasgow NimbleGen next-generation sequencing (NGS). Phylogenetic analysis was carried out by generating an uncorrected nucleotide p-distance tree from the complete coding regions of our sequences., Results: Of 91 African patients, 47 (52%) were infected with an unusual subtype. Fourteen novel, as yet undesignated subtypes (G1*), were identified by NGS. Three individuals were infected with the same subtype, now designated as subtype 1p. Baseline sequences were available for 22 patients; 18/22 (82%) had baseline NS5A resistance-associated substitutions (RASs). Sustained virological response (SVR) was achieved in 56/63 (89%) overall, yet only in 21/28 (75%) of those with unusual G1 subtypes, with failure in 3/16 G1*, 1/2 G1p and 3/3 in G1l. Six treatment failures occurred with sofosbuvir/ledipasvir compared to 1 failure on a PI-based regimen. The SVR rate for all other genotypes and subtypes was 35/35 (100%)., Conclusions: Most individuals in an unselected cohort of African patients were infected with an unusual genotype, including novel subtype 1p. The SVR rate of those with unusual G1 subtypes was 75%, raising concern about expansion of DAAs across Africa. Depending on the regimen used, higher failure rates in African cohorts could jeopardise HCV elimination., Lay Summary: Direct-acting antiviral medications are able to cure hepatitis C in the majority of patients. The most common genotype of hepatitis C in Europe and the United States is genotype 1a or 1b and most clinical trials focused on these genotypes. We report that in a group of African patients, most of them had unusual (non-1a/1b) genotype 1 subtypes, and that the cure rate in these unusual genotypes was lower than in genotypes 1a and 1b., (Copyright © 2019 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Introduction and Objectives: Direct antiviral agents (DAAs) are very efficient in inhibiting hepatitis C virus and might be used to treat infections caused by other flaviviruses whose worldwide detection has recently increased. The aim of this study was to verify the efficacy of DAAs in inhibiting yellow fever virus (YFV) by using drug repositioning (a methodology applied in the pharmaceutical industry to identify new uses for approved drugs)., Materials and Methods: Three DAAs were evaluated: daclatasvir, sofosbuvir and ledipasvir or their combinations. For in vitro assays, the drugs were diluted in 100% dimethyl sulfoxide. Vaccine strain 17D and a 17D strain expressing the reporter fluorescent protein were used in the assays. A fast and reliable cell-based screening assay using Vero cells or Huh-7 cells (a hepatocyte-derived carcinoma ell line) was carried out. Two patients who acquired yellow fever virus with acute liver failure were treated with sofosbuvir for one week as a compassionate use., Results: Using a high-content screening assay, we verified that sofosbuvir presented the best antiviral activity against YFV. Moreover, after an off-label treatment with sofosbuvir, the two female patients diagnosed with yellow fever infection displayed a reduction in blood viremia and an improvement in the course of the disease, which was observed in the laboratory medical parameters related to disease evolution., Conclusions: Sofosbuvir may be used as an option for treatment against YFV until other drugs are identified and approved for human use. These results offer insights into the role of nonstructural protein 5 (NS5) in YFV inhibition and suggest that nonstructural proteins may be explored as drug targets for YFV treatment., (Copyright © 2019 Fundación Clínica Médica Sur, A.C. Published by Elsevier España, S.L.U. All rights reserved.)

Herein, we develop a novel mitochondria-targetable fluorescence probe (FVPI) based on fluorene cation derivative. This mitochondria-targetable fluorescence probe exhibits large Stokes shift in various solutions. In addition, FVPI displays numerous advantages, including high photostability, low cytotoxicity, and two-photon properties. View of the above features, FVPI is successfully capable of imaging mitochondria in biological systems with three different sets of signals. This finding will provide a new platform for the constructing mitochondria-targetable fluorescent probes with excellent optical properties.

P-glycoprotein (ABCB1), an ATP-binding-cassette efflux transporter, limits intestinal absorption of its substrates and is a common site of drug-drug interactions (DDIs). ABCB1 has been suggested to interact with many antivirals used to treat HIV and/or chronic hepatitis C virus (HCV) infections. Using bidirectional transport experiments in Caco-2 cells and a recently established ex vivo model of accumulation in precision-cut intestinal slices (PCIS) prepared from rat ileum or human jejunum, we evaluated the potential of anti-HIV and anti-HCV antivirals to inhibit intestinal ABCB1. Lopinavir, ritonavir, saquinavir, atazanavir, maraviroc, ledipasvir, and daclatasvir inhibited the efflux of a model ABCB1 substrate, rhodamine 123 (RHD123), in Caco-2 cells and rat-derived PCIS. Lopinavir, ritonavir, saquinavir, and atazanavir also significantly inhibited RHD123 efflux in human-derived PCIS, while possible interindividual variability was observed in the inhibition of intestinal ABCB1 by maraviroc, ledipasvir, and daclatasvir. Abacavir, zidovudine, tenofovir disoproxil fumarate, etravirine, and rilpivirine did not inhibit intestinal ABCB1. In conclusion, using recently established ex vivo methods for measuring drug accumulation in rat- and human-derived PCIS, we have demonstrated that some antivirals have a high potential for DDIs on intestinal ABCB1. Our data help clarify the molecular mechanisms responsible for reported increases in the bioavailability of ABCB1 substrates, including antivirals and drugs prescribed to treat comorbidity. These results could help guide the selection of combination pharmacotherapies and/or suitable dosing schemes for patients infected with HIV and/or HCV., (Copyright © 2019 American Society for Microbiology.)

Drug-loading hydrogels are promising candidates in the bioengineering research field; nevertheless, hydrophobic drug loading into a hydrophilic carrier system remains unsolved and is full of challenges. In this work, following the potential dual interactions between peptides and aromatic drugs, we developed a potent hybrid hydrogel formation method, namely, "peptide-/drug-directed self-assembly". The hybrid hydrogels were synthesized using polyethylene glycol (PEG)-based Fmoc-FF peptide hybrid polyurethane, in which curcumin could be encapsulated through self-assembly with Fmoc-FF peptide via π-π stacking. On the basis of this, curcumin loading capacity could be improved to as high as 3.3 wt % with sustained release. In addition, the curcumin loading enhanced the hydrogel mechanical properties from 4 kPa to over 10 kPa, similar to that of natural soft tissues. Furthermore, the hydrogels were injectable with self-healing properties since the Fmoc-FF peptide/curcumin coassembly was noncovalent and reversible. Spectroscopy results confirmed the existence of the coassembly of Fmoc-FF peptide/curcumin. Further in vivo experiments effectively demonstrated that the hydrogels could improve the cutaneous wound healing in a full-thickness skin defected model. This peptide-/drug-directed self-assembly of hybrid polyurethane hydrogel could be used as a promising platform for tissue-engineering scaffold and biomedical application.

In our work, 19 novel 4,5-diazafluorene derivatives (11a-d, 12a-d, 13a-d, 14a-c, 15c, 16a-c) bearing a 1,3-disubstituted pyrazol/thioxothiazolidinone or thioxothiazolidinone-oxadiazole moieties were designed, synthesized, preliminarily explored for their antitumor activities and in vitro mechanism. All compounds showed different values of antiproliferative activity against A549, AGS, HepG2 and MCF-7 cell lines through CCK-8. Especially, the compound 14c exhibited the strongest activity and best selectivity against A549 cells with an IC 50 1.13 μM and an SI value of 7.01 relative to MRC-5 cells, which was better than cisplatin (SI = 1.80) as a positive control. Experimental results at extracellular level demonstrated that compounds 14a-c could strongly interact with the G-quadruplex(es) formed in a 26 nt telomeric G-rich DNA, in particular, the 14c exhibits quite strong binding affinity with an association equilibrium constant (K A ) of 7.04(±0.16) × 10 7  M -1 and more than 1000-fold specificity to G4-DNA over ds-DNA and Mut-DNA at the compound/G4-DNA ratio of 1:1. Further trap assay ascertained that compounds 14a-c owned strong inhibitory ability of telomerase activity in A549 cells, suggesting that these compounds have great possibility to target telomeric G-quadruplexes and consequently indirectly inhibit the telomerase activity. In addition, it is worthy of note that the remarkable inhibitory effects of 14a-c on the mobility of tested cancer cells were observed by wound healing assays. Furthermore, molecular docking and UV-Vis spectral results unclose the rationale for the interaction of compounds with such G-quadruplex(es). These results indicate that the growth and metastasis inhibition of cancer cells mediated by these 4,5-diazafluorene derivatives possibly result from their interaction with telomeric G-quadruplexes, suggesting that 4,5-diazafluorene derivatives, especially 14c, possess potential as anticancer drugs., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Fluorene-9-bisphenol (BHPF), a new derivative of bisphenol A (BPA), has been introduced for treatment with estrogen-related tumors, such as endometrial cancer. This study investigated the potential mechanism underlying the action of BHPF against endometrial cancer in vitro. We used the cell counting kit-8 (CCK8) method on Ishikawa cells to screen sub-lethal doses of BHPF and established the optimal concentration at which BHPF influenced the proliferation of Ishikawa cells. Effect of BHPF on cell migration and invasion was investigated by cell scratch assay and transwell assay, respectively. Expression levels of epithelial-mesenchymal transition (EMT)-related proteins were detected by Western blot analysis. BHPF was found to inhibit the proliferation of Ishikawa cells, whose migration and invasion abilities were also reduced. Western blot indicated that BHPF can significantly inhibit the EMT process of Ishikawa cells by blocking transforming growth factor-β (TGF-β) signaling pathway. This is the first report of the effect of BHPF on the biological behavior of endometrial cancer cells and its inhibition of endometrial cancer progression by repressing both endometrial cell proliferation and epithelial-mesenchymal transition, hence suggesting it as a novel anti-cancer drug. Graphical abstract Schematic representation of the molecular basis underlying BHPF treatment. BHPF repressed the EMT process by regulating EMT-related genes, such as E-cadherin, N-cadherin, and vimentin as well as the TGF-β signaling pathway-related genes, including p-Smad2/3 and slug, in a BHPF-dependent manner.

We evaluated the protective effects of hypoxylonol C and 4,5,4',5'-tetrahydroxy-1,1'-binaphthyl (BNT) isolated from Annulohypoxylon annulatum on pancreatic β-cell apoptosis, using the β-cell toxin streptozotocin (STZ). Hypoxylonol C and BNT restored the STZ-induced decrease in INS-1 cell viability in a dose-dependent manner. In addition, treatment of INS-1 cells with 50 μM STZ resulted in an increase in apoptotic cell death, which was observed as annexin V fluorescence intensity. Apoptotic cell death was decreased by co-treatment with 100 μM hypoxylonol C and 100 μM BNT. Similarly, STZ caused a marked increase in the expression of cleaved caspase-8, caspase-3, Bax, and poly (ADP-ribose) polymerase (PARP), as well as a decrease in the expression of B-cell lymphoma 2 (Bcl-2), which was reversed by co-treatment with 100 μM hypoxylonol C and 100 μM BNT. These findings suggest that hypoxylonol C and BNT play an important role in protecting pancreatic β-cells against apoptotic damage., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The metacercariae of the Clonorchis sinensis liver fluke excyst in the duodenum of mammalian hosts, and the newly excysted juveniles (CsNEJs) migrate along the bile duct via bile chemotaxis. Cholic acid is a major component of bile that induces this migration. We investigated the neuronal control of chemotactic behavior of CsNEJs toward cholic acid. The migration of CsNEJs was strongly inhibited at sub-micromolar concentration by dopamine D1 (LE-300 and SKF-83566), D2 (spiramide, nemonapride, and sulpiride), and D3 (GR-103691 and NGB-2904) receptor antagonists, as well as a dopamine reuptake inhibitor (BTCP). Neuropeptides, FMRFamide, peptide YY, and neuropeptide Y were also potent inhibitors of chemotaxis. Meanwhile, serotonergic, glutamatergic, and cholinergic inhibitors did not affect chemotaxis, with the exception of fluoxetine and CNQX. Confocal immunofluorescence analysis indicated that dopaminergic and cholinergic neurons were colocalized in the somatic muscle tissues of adult C. sinensis. Our findings suggest that dopaminergic neurons and neuropeptides play a major role in the chemotactic migration of CsNEJs to bile, and their inhibitors or modulators could be utilized to prevent their migration from the bile duct., Competing Interests: The authors have declared that no competing interests exist.

Direct arylation polymerization (DARP) is a novel approach to obtain conjugated polymers (CPs) through the straightforward C-H activation of monomer building blocks. In this work, a convenient DARP method with high efficiency and excellent regioselectivity is developed to synthesize a series of donor-acceptor (D-A)-type CPs composed of electron-acceptor moiety fluorenones (FOs) and various electron-donor moieties. CPs with different band gaps are obtained in good yields and display large Stokes shifts up to 295 nm. Two ionic CPs, PFOP-NEt3(+) and PFOP-COO(-), were prepared in a polar solvent system to improve the water solubility and biocompatibility using the proposed DARP method. Detailed photophysical studies of these two CPs suggest that both solvation and hydrogen bonds play important roles in determining the polymers' spectroscopic properties. Further studies of the cationic polymer PFOP-NEt3(+) in cell imaging demonstrate its potential application in labeling cell membranes and lysosomes given its low cytotoxicity, excellent photostability, and specific subcellular localization.

Insulin plays a key role in glucose homeostasis and is hence used to treat hyperglycemia, the main characteristic of diabetes mellitus. Annulohypoxylon annulatum is an inedible ball-shaped wood-rotting fungus, and hypoxylon F is one of the major compounds of A. annulatum . The aim of this study is to evaluate the effects of hypoxylonol F isolated from A. annulatum on insulin secretion in INS-1 pancreatic β-cells and demonstrate the molecular mechanisms involved. Glucose-stimulated insulin secretion (GSIS) values were evaluated using a rat insulin ELISA kit. Moreover, the expression of proteins related to pancreatic β-cell metabolism and insulin secretion was evaluated using Western blotting. Hypoxylonol F isolated from A. annulatum was found to significantly enhance glucose-stimulated insulin secretion without inducing cytotoxicity. Additionally, hypoxylonol F enhanced insulin receptor substrate-2 (IRS-2) levels and activated the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway. Interestingly, it also modulated the expression of peroxisome proliferator-activated receptor γ (PPARγ) and pancreatic and duodenal homeobox 1 (PDX-1). Our findings showed that A. annulatum and its bioactive compounds are capable of improving insulin secretion by pancreatic β-cells. This suggests that A. annulatum can be used as a therapeutic agent to treat diabetes.