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PloS One 2016Amyloid formation of the human plasma protein transthyretin (TTR) is associated with several human disorders, including familial amyloidotic polyneuropathy (FAP) and...
Amyloid formation of the human plasma protein transthyretin (TTR) is associated with several human disorders, including familial amyloidotic polyneuropathy (FAP) and senile systemic amyloidosis. Dissociation of TTR's native tetrameric assembly is the rate-limiting step in the conversion into amyloid, and this feature presents an avenue for intervention because binding of an appropriate ligand to the thyroxin hormone binding sites of TTR stabilizes the native tetrameric assembly and impairs conversion into amyloid. The desired features for an effective TTR stabilizer include high affinity for TTR, high selectivity in the presence of other proteins, no adverse side effects at the effective concentrations, and a long half-life in the body. In this study we show that the commonly used flame retardant tetrabromobisphenol A (TBBPA) efficiently stabilizes the tetrameric structure of TTR. The X-ray crystal structure shows TBBPA binding in the thyroxine binding pocket with bromines occupying two of the three halogen binding sites. Interestingly, TBBPA binds TTR with an extremely high selectivity in human plasma, and the effect is equal to the recently approved drug tafamidis and better than diflunisal, both of which have shown therapeutic effects against FAP. TBBPA consequently present an interesting scaffold for drug design. Its absorption, metabolism, and potential side-effects are discussed.
Topics: Amyloid; Amyloidosis; Benzoxazoles; Binding Sites; Cell Line, Tumor; Crystallography, X-Ray; Diflunisal; Drug Design; Excipients; Half-Life; Humans; Ligands; Polybrominated Biphenyls; Prealbumin; Protein Binding; Thyroxine
PubMed: 27093678
DOI: 10.1371/journal.pone.0153529 -
Antimicrobial Agents and Chemotherapy Sep 2017is a highly infectious Gram-negative intracellular pathogen that causes tularemia. Because of its potential as a bioterrorism agent, there is a need for new therapeutic...
is a highly infectious Gram-negative intracellular pathogen that causes tularemia. Because of its potential as a bioterrorism agent, there is a need for new therapeutic agents. We therefore developed a whole-animal - pathosystem for high-throughput screening to identify and characterize potential therapeutic compounds. We found that the p38 mitogen-activate protein (MAP) kinase cascade is involved in the immune response to , and we developed a robust -mediated killing assay with a Z' factor consistently of >0.5, which was then utilized to screen a library of FDA-approved compounds that included 1,760 small molecules. In addition to clinically used antibiotics, five FDA-approved drugs were also identified as potential hits, including the anti-inflammatory drug diflunisal that showed anti- activity Moreover, the nonsteroidal anti-inflammatory drug (NSAID) diflunisal, at 4× MIC, blocked the replication of an live vaccine strain (LVS) in primary human macrophages and nonphagocytic cells. Diflunisal was nontoxic to human erythrocytes and HepG2 human liver cells at concentrations of ≥32 μg/ml. Finally, diflunisal exhibited synergetic activity with the antibiotic ciprofloxacin in both a checkerboard assay and a macrophage infection assay. In conclusion, the liquid - LVS assay described here allows screening for anti- compounds and suggests that diflunisal could potentially be repurposed for the management of tularemia.
Topics: Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents; Bacterial Vaccines; Caenorhabditis elegans; Cell Line, Tumor; Ciprofloxacin; Erythrocytes; Francisella tularensis; Hep G2 Cells; Humans; Liver; Macrophages; Vaccines, Attenuated; p38 Mitogen-Activated Protein Kinases
PubMed: 28652232
DOI: 10.1128/AAC.00310-17 -
Frontiers in Genetics 2020Genetic and environmental factors, alone or in combination, contribute to the pathogenesis of autism spectrum disorder (ASD). Although many protein-coding genes have now...
Genetic and environmental factors, alone or in combination, contribute to the pathogenesis of autism spectrum disorder (ASD). Although many protein-coding genes have now been identified as disease risk genes for ASD, a detailed illustration of long non-coding RNAs (lncRNAs) associated with ASD remains elusive. In this study, we first identified ASD-related lncRNAs based on genomic variant data of individuals with ASD from a twin study. In total, 532 ASD-related lncRNAs were identified, and 86.7% of these ASD-related lncRNAs were further validated by an independent copy number variant (CNV) dataset. Then, the functions and associated biological pathways of ASD-related lncRNAs were explored by enrichment analysis of their three different types of functional neighbor genes (i.e., genomic neighbors, competing endogenous RNA (ceRNA) neighbors, and gene co-expression neighbors in the cortex). The results have shown that most of the functional neighbor genes of ASD-related lncRNAs were enriched in nervous system development, inflammatory responses, and transcriptional regulation. Moreover, we explored the differential functions of ASD-related lncRNAs in distinct brain regions by using gene co-expression network analysis based on tissue-specific gene expression profiles. As a set, ASD-related lncRNAs were mainly associated with nervous system development and dopaminergic synapse in the cortex, but associated with transcriptional regulation in the cerebellum. In addition, a functional network analysis was conducted for the highly reliable functional neighbor genes of ASD-related lncRNAs. We found that all the highly reliable functional neighbor genes were connected in a single functional network, which provided additional clues for the action mechanisms of ASD-related lncRNAs. Finally, we predicted several potential drugs based on the enrichment of drug-induced pathway sets in the ASD-altered biological pathway list. Among these drugs, several (e.g., amoxapine, piperine, and diflunisal) were partly supported by the previous reports. In conclusion, ASD-related lncRNAs participated in the pathogenesis of ASD through various known biological pathways, which may be differential in distinct brain regions. Detailed investigation into ASD-related lncRNAs can provide clues for developing potential ASD diagnosis biomarkers and therapy.
PubMed: 33193567
DOI: 10.3389/fgene.2020.00849 -
British Journal of Clinical Pharmacology Sep 1985Single dose pharmacokinetics of oxazepam, 30 mg, have been studied in six healthy male volunteers in the absence of diflunisal and during continuous treatment with...
Single dose pharmacokinetics of oxazepam, 30 mg, have been studied in six healthy male volunteers in the absence of diflunisal and during continuous treatment with diflunisal 500 mg twice daily. During diflunisal treatment, peak plasma concentration of oxazepam significantly decreased from 387 +/- 18 ng ml-1 (mean +/- s.e. mean) to 241 +/- 10 ng ml-1 and total area under the plasma concentration-time curve (AUC) significantly decreased from 5536 +/- 819 ng ml-1 h to 4643 +/- 562 ng ml-1 h. The AUC of oxazepam glucuronide significantly increased from 4771 +/- 227 ng ml-1 h to 8116 +/- 644 ng ml-1 h and its elimination half-life increased from 10.0 +/- 0.6 h to 13.0 +/- 1.0 h. Renal clearance for oxazepam glucuronide was significantly reduced from 74 +/- 2 ml min-1 to 46 +/- 3 ml min-1. In vitro, diflunisal, at concentrations of 125 to 1000 micrograms ml-1, significantly displaced oxazepam from its plasma protein binding, the free fraction of oxazepam increasing by 28 to 56%. The free fraction of oxazepam glucuronide, ex vivo, increased by 49 +/- 5% (n = 3) during concomitant diflunisal treatment. These data suggest that the observed interaction between oxazepam and diflunisal results from a presystemic displacement of oxazepam from its plasma protein binding sites by diflunisal and from an inhibition of the tubular secretion of oxazepam glucuronide by the glucuronides of diflunisal.
Topics: Adult; Blood Proteins; Diflunisal; Humans; Kinetics; Male; Oxazepam; Protein Binding; Salicylates
PubMed: 4041343
DOI: 10.1111/j.1365-2125.1985.tb05065.x -
Antibiotics (Basel, Switzerland) Apr 2022The bacterial cell wall is essential for protecting bacteria from the surrounding environment and maintaining the integrity of bacteria cells. The MurA enzyme, which is...
The bacterial cell wall is essential for protecting bacteria from the surrounding environment and maintaining the integrity of bacteria cells. The MurA enzyme, which is an essential enzyme involved in bacterial cell wall synthesis, could be a good drug target for antibiotics. Although fosfomycin is used clinically as a MurA inhibitor, resistance to this antibiotic is a concern. Here we used molecular docking-based virtual screening approaches to identify potential MurA inhibitors from 1.412 million compounds from three databases. Thirty-three top compounds from virtual screening were experimentally tested in (Gram-positive bacterium) and (Gram-negative bacterium). Compound 2-Amino-5-bromobenzimidazole (S17) showed growth inhibition effect in both and , with the same Minimum Inhibitory Concentration (MIC) value of 0.5 mg/mL. Compound 2-[4-(dimethylamino)benzylidene]--nitrohydrazinecarboximidamide (C1) had growth inhibition effect only in , with a MIC value of 0.5 mg/mL. Two FDA-approved drugs, albendazole (S4) and diflunisal (S8), had a growth inhibition effect only in , with a MIC value of 0.0625 mg/mL. The identified MurA inhibitors could be potential novel antibiotics. Furthermore, they could be potential fosfomycin substitutes for the fosfomycin-resistant strains.
PubMed: 35453279
DOI: 10.3390/antibiotics11040528 -
PloS One 2015Drug repositioning has shorter developmental time, lower cost and less safety risk than traditional drug development process. The current study aims to repurpose...
Drug repositioning has shorter developmental time, lower cost and less safety risk than traditional drug development process. The current study aims to repurpose marketed drugs and clinical candidates for new indications in diabetes treatment by mining clinical 'omics' data. We analyzed data from genome wide association studies (GWAS), proteomics and metabolomics studies and revealed a total of 992 proteins as potential anti-diabetic targets in human. Information on the drugs that target these 992 proteins was retrieved from the Therapeutic Target Database (TTD) and 108 of these proteins are drug targets with drug projects information. Research and preclinical drug targets were excluded and 35 of the 108 proteins were selected as druggable proteins. Among them, five proteins were known targets for treating diabetes. Based on the pathogenesis knowledge gathered from the OMIM and PubMed databases, 12 protein targets of 58 drugs were found to have a new indication for treating diabetes. CMap (connectivity map) was used to compare the gene expression patterns of cells treated by these 58 drugs and that of cells treated by known anti-diabetic drugs or diabetes risk causing compounds. As a result, 9 drugs were found to have the potential to treat diabetes. Among the 9 drugs, 4 drugs (diflunisal, nabumetone, niflumic acid and valdecoxib) targeting COX2 (prostaglandin G/H synthase 2) were repurposed for treating type 1 diabetes, and 2 drugs (phenoxybenzamine and idazoxan) targeting ADRA2A (Alpha-2A adrenergic receptor) had a new indication for treating type 2 diabetes. These findings indicated that 'omics' data mining based drug repositioning is a potentially powerful tool to discover novel anti-diabetic indications from marketed drugs and clinical candidates. Furthermore, the results of our study could be related to other disorders, such as Alzheimer's disease.
Topics: Adrenergic alpha-2 Receptor Antagonists; Cyclooxygenase 2 Inhibitors; Data Mining; Databases, Pharmaceutical; Diabetes Mellitus; Drug Repositioning; Gene Expression Profiling; Genome-Wide Association Study; Humans; Hypoglycemic Agents; Metabolomics; Proteomics; Receptors, N-Methyl-D-Aspartate
PubMed: 25946000
DOI: 10.1371/journal.pone.0126082 -
Journal of the American Heart... Oct 2020Background The emergence of specific therapies for transthyretin cardiac amyloidosis (CA) warrants the need for a systematic review of the literature. Methods and...
Background The emergence of specific therapies for transthyretin cardiac amyloidosis (CA) warrants the need for a systematic review of the literature. Methods and Results A systematic review of the literature was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was performed on MEDLINE, PubMed, and Embase databases on November 29, 2019. Studies were selected based on the following predefined eligibility criteria: English-language randomized controlled trials (RCTs), non-RCTs, or observational studies, which included adult patients with variant/wild-type transthyretin-CA, assessed specific therapies for transthyretin-CA, and reported cardiovascular outcomes. Relevant data were extracted to a predefined template. Quality assessment was based on National Institute for Health and Care Excellence recommendations (RCTs) or a checklist by Downs and Black (non-RCTs). From 1203 records, 24 publications were selected, describing 4 RCTs (6 publications) and 16 non-RCTs (18 publications). Tafamidis was shown to significantly improve all-cause mortality and cardiovascular hospitalizations and reduce worsening in 6-minute walk test, Kansas City Cardiomyopathy Questionnaire-Overall Summary score, and NT-proBNP (N-terminal pro-B-type natriuretic peptide) in variant/wild-type transthyretin-CA. Patisiran showed promising results in a subgroup analysis of patients with variant transthyretin-CA, which have to be confirmed in RCTs. Inotersen showed conflicting results on cardiac imaging parameters. The one study on AG10 had only a 1-month duration and cardiovascular end points were exploratory and limited to cardiac biomarkers. Limited evidence from noncomparative single-arm small non-RCTs existed for diflunisal, epigallocatechin-3-gallate (green tea extract), and doxycycline+tauroursodeoxycholic acid/ursodeoxycholic acid. Conclusions This systematic review of the literature supports the use of tafamidis in wild-type and variant transthyretin-CA. Novel therapeutic targets including transthyretin gene silencers are currently under investigation.
Topics: Amyloid Neuropathies, Familial; Benzoxazoles; Cardiomyopathies; Cardiovascular Agents; Genetic Therapy; Humans
PubMed: 32969287
DOI: 10.1161/JAHA.120.016614 -
Cancers May 2021Cyclin D1 () and cyclin-dependent kinase 4 () both play significant roles in regulating cell cycle progression, while polo-like kinase 1 () regulates cell...
Cyclin D1 () and cyclin-dependent kinase 4 () both play significant roles in regulating cell cycle progression, while polo-like kinase 1 () regulates cell differentiation and tumor progression, and activates cancer stem cells (CSCs), with the cluster of differentiation 44 () surface marker mostly being expressed. These oncogenes have emerged as promoters of metastasis in a variety of cancer types. In this study, we employed comprehensive computational and bioinformatics analyses to predict drug targets of our novel small molecules, NSC765600 and NSC765691, respectively derived from diflunisal and fostamatinib. The target prediction tools identified as target genes for NSC765600 and NSC765691 compounds. Additionally, the results of our in silico molecular docking analysis showed unique ligand-protein interactions with putative binding affinities of NSC765600 and NSC765691 with oncogenic signaling pathways. Moreover, we used drug-likeness precepts as our guidelines for drug design and development, and found that both compounds passed the drug-likeness criteria of molecular weight, polarity, solubility, saturation, flexibility, and lipophilicity, and also exhibited acceptable pharmacokinetic properties. Furthermore, we used development therapeutics program (DTP) algorithms and identified similar fingerprints and mechanisms of NSC765600 and NSC765691 with synthetic compounds and standard anticancer agents in the NCI database. We found that NSC765600 and NSC765691 displayed antiproliferative and cytotoxic effects against a panel of NCI-60 cancer cell lines. Based on these finding, NSC765600 and NSC765691 exhibited satisfactory levels of safety with regard to toxicity, and met all of the required criteria for drug-likeness precepts. Currently, further in vitro and in vivo investigations in tumor-bearing mice are in progress to study the potential treatment efficacies of the novel NSC765600 and NSC765691 small molecules.
PubMed: 34063946
DOI: 10.3390/cancers13112523 -
British Journal of Clinical Pharmacology Sep 2009To characterize: i) the kinetics of aldosterone (ALDO) 18beta-glucuronidation using human liver and human kidney microsomes and identify the human UGT enzyme(s)...
AIMS
To characterize: i) the kinetics of aldosterone (ALDO) 18beta-glucuronidation using human liver and human kidney microsomes and identify the human UGT enzyme(s) responsible for ALDO 18beta-glucuronidation and ii) the inhibition of ALDO 18beta-glucuronidation by non-selective NSAIDs.
METHODS
Using HPLC and LC-MS methods, ALDO 18beta-glucuronidation was characterized using human liver (n= 6), human kidney microsomes (n= 5) and recombinant human UGT 1A1, 1A3, 1A4, 1A5, 1A6, 1A7, 1A8, 1A9, 1A10, 2B4, 2B7, 2B10, 2B15, 2B17 and 2B28 as the enzyme sources. Inhibition of ALDO 18beta-glucuronidation was investigated using alclofenac, cicloprofen, diclofenac, diflunisal, fenoprofen, R- and S-ibuprofen, indomethacin, ketoprofen, ketorolac, meclofenamic acid, mefenamic acid, S-naproxen, pirprofen and tiaprofenic acid. A rank order of inhibition (IC(50)) was established and the mechanism of inhibition investigated using diclofenac, S-ibuprofen, indomethacin, mefenamic acid and S-naproxen.
RESULTS
ALDO 18beta-glucuronidation by hepatic and renal microsomes exhibited Michaelis-Menten kinetics. Mean (+/-SD) K(m), V(max) and CL(int) values for HLM and HKCM were 509 +/- 137 and 367 +/- 170 microm, 1075 +/- 429 and 1110 +/- 522 pmol min(-1) mg(-1), and 2.36 +/- 1.12 and 3.91 +/- 2.35 microl min(-1) mg(-1), respectively. Of the UGT proteins, only UGT1A10 and UGT2B7 converted ALDO to its 18beta-glucuronide. All NSAIDs investigated inhibited ALDO 18beta-G formation by HLM, HKCM and UGT2B7. The rank order of inhibition (IC(50)) of renal and hepatic ALDO 18beta-glucuronidation followed the general trend: fenamates > diclofenac > arylpropionates.
CONCLUSION
A NSAID-ALDO interaction in vivo may result in elevated intra-renal concentrations of ALDO that may contribute to the adverse renal effects of NSAIDs and their effects on antihypertensive drug response.
Topics: Adult; Aged; Aldosterone; Anti-Inflammatory Agents, Non-Steroidal; Chromatography, High Pressure Liquid; Female; Glucuronides; Glucuronosyltransferase; Humans; Inhibitory Concentration 50; Kidney; Kinetics; Liver; Male; Microsomes; Middle Aged
PubMed: 19740398
DOI: 10.1111/j.1365-2125.2009.03469.x -
International Journal of Molecular... Sep 2019The enzyme phospholipase C gamma 1 (PLCγ1) has been identified as a potential drug target of interest for various pathological conditions such as immune disorders,...
The enzyme phospholipase C gamma 1 (PLCγ1) has been identified as a potential drug target of interest for various pathological conditions such as immune disorders, systemic lupus erythematosus, and cancers. Targeting its SH3 domain has been recognized as an efficient pharmacological approach for drug discovery against PLCγ1. Therefore, for the first time, a combination of various biophysical methods has been employed to shed light on the atomistic interactions between PLCγ1 and its known binding partners. Indeed, molecular modeling of PLCγ1 with SLP76 peptide and with previously reported inhibitors (ritonavir, anethole, daunorubicin, diflunisal, and rosiglitazone) facilitated the identification of the common critical residues (Gln805, Arg806, Asp808, Glu809, Asp825, Gly827, and Trp828) as well as the quantification of their interaction through binding energies calculations. These features are in agreement with previous experimental data. Such an in depth biophysical analysis of each complex provides an opportunity to identify new inhibitors through pharmacophore mapping, molecular docking and MD simulations. From such a systematic procedure, a total of seven compounds emerged as promising inhibitors, all characterized by a strong binding with PLCγ1 and a comparable or higher binding affinity to ritonavir (∆G < -25 kcal/mol), one of the most potent inhibitor reported till now.
Topics: Enzyme Inhibitors; Humans; Molecular Docking Simulation; Peptides; Phospholipase C gamma; Protein Binding; Protein Domains
PubMed: 31548507
DOI: 10.3390/ijms20194721