Literature Watch

The role of cytochrome P450 pharmacogenomics in chronic non-cancer pain patients.

Pharmacogenomics - Sat, 2016-07-09 08:37

The role of cytochrome P450 pharmacogenomics in chronic non-cancer pain patients.

Expert Opin Drug Metab Toxicol. 2016 Jul 7;

Authors: Tverdohleb T, Dinc B, Knezevic I, Candido KD, Knezevic NN

Abstract
INTRODUCTION: Pharmacogenomics is the field that studies an individualized treatment approach for patients' medication regimen that can impact drug safety, productivity, and personalized health care. Pharmacogenomics characterizes the genetic differences in metabolic pathways which can affect a patient's individual responses to drug treatments.
AREAS COVERED: The various responses to pharmacological agents are mainly determined by the different types of genetic variants of the CYP450. CYP2D6 polymorphism is well known for its variation in the metabolism of drugs from many therapeutic arenas, including some analgesic drugs such as codeine, hydromorphone, oxycodone and tramadol. Allele combinations determine the phenotypic expression, characterized as either: extensive metabolizer, intermediate metabolizer, ultra-rapid metabolizer and poor metabolizer.
EXPERT OPINION: The Human Genome Project (HGP) revolutionized the future of medicine and the way health care providers approach individualized patient treatment, and chronic pain management is one of those areas. The key findings in the literature appear to be related to the CYP2D6 expression and its high polymorphism influencing the metabolism of opioid medications, and the impact of that on the patient's therapeutic outcome thus exemplifying the importance of genetic testing for CYP2D6 in the process of physician therapeutic decision making.

PMID: 27388970 [PubMed - as supplied by publisher]

Categories: Literature Watch

SNP genetic polymorphisms of MDR-1, CYP1A2 and CYPB11 genes in four canine breeds upon toxicological evaluation.

Pharmacogenomics - Sat, 2016-07-09 08:37
Related Articles

SNP genetic polymorphisms of MDR-1, CYP1A2 and CYPB11 genes in four canine breeds upon toxicological evaluation.

J Vet Sci. 2015;16(3):273-80

Authors: Gagliardi R, Llambí S, Arruga MV

Abstract
The fields of pharmacogenetics and pharmacogenomics have become increasingly promising regarding the clinical application of genetic data to aid in prevention of adverse reactions. Specific screening tests can predict which animals express modified proteins or genetic sequences responsible for adverse effects associated with a drug. Among the genetic variations that have been investigated in dogs, the multidrug resistance gene (MDR) is the best studied. However, other genes such as CYP1A2 and CYP2B11 control the protein syntheses involved in the metabolism of many drugs. In the present study, the MDR-1, CYP1A2 and CYP2B11 genes were examined to identify SNP polymorphisms associated with these genes in the following four canine breeds: Uruguayan Cimarron, Border Collie, Labrador Retriever and German Shepherd. The results revealed that several SNPs of the CYP1A2 and CYP2B11 genes are potential targets for drug sensitivity investigations.

PMID: 25797294 [PubMed - indexed for MEDLINE]

Categories: Literature Watch

("orphan disease" OR "rare disease" OR "orphan diseases" OR "rare diseases"); +7 new citations

Orphan or Rare Diseases - Fri, 2016-07-08 06:53

7 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

("orphan disease" OR "rare disease" OR "orphan diseases" OR "rare diseases")

These pubmed results were generated on 2016/07/08

PubMed comprises more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Categories: Literature Watch

Current issues concerning drug development for pediatric hematologic malignancies.

Drug Repositioning - Fri, 2016-07-08 06:52

Current issues concerning drug development for pediatric hematologic malignancies.

Rinsho Ketsueki. 2016;57(6):693-700

Authors: Sekimizu M

Abstract
Cure rates for pediatric hematologic malignancies (HM) have improved dramatically due to the intensive use of conventional chemotherapy and hematopoietic stem cell transplantation. However, many children still die of their disease or treatment-related toxicities. Even in patients experiencing an apparent cure, there can be significant acute and late complications of treatment. Further improvements of therapy will likely depend on the development of new therapeutic strategies. Immune-based therapy, for example monoclonal antibody-based and adoptive T-cell therapies, offers an attractive alternative that has emerged as a potent treatment strategy. Drug repositioning of molecular target drugs is now receiving remarkable attention, especially that based on recent genome wide studies. However, there are many obstacles to overcome in developing these novel drugs for pediatric patients. Pediatric drug development is difficult in itself because many of these agents are not profitable, largely due to their being too few patients, preclinical models are limited, there are too few formulations for children, special ethical considerations must be addressed when treating children and so on. Obstacles to the development of new drugs are a characteristic feature of pediatric HM. Furthermore, the approach to developing drugs for pharmaceutical approval is quite different from that to developing new therapies using approved drugs and is not well-known among investigators. Although many challenges remain in pediatric hematologic anticancer drug development, none are insurmountable.

PMID: 27384847 [PubMed - as supplied by publisher]

Categories: Literature Watch

Impact of Transporter Polymorphisms on Drug Development: Is It Clinically Significant?

Pharmacogenomics - Fri, 2016-07-08 06:52

Impact of Transporter Polymorphisms on Drug Development: Is It Clinically Significant?

J Clin Pharmacol. 2016 Jul;56 Suppl 7:S40-S58

Authors: McLean C, Wilson A, Kim RB

Abstract
Drug transporters are becoming increasingly recognized as relevant to the drug development process. This may be a reflection of increasing target complexity and the need for high-affinity interaction with drug targets that minimize off-target side effects. Moreover, as new molecular entities (NMEs) become larger in size and amphipathic in nature, interaction with drug transporters, both uptake as well as efflux, becomes increasingly likely. In some cases transporters may limit the absorption or organ-specific entry of NMEs, whereas in other cases transporters may enhance their absorption or tissue accumulation. Indeed, in some cases, transporters may prove to be a therapeutic target. Accordingly, a better understanding of potentially clinically relevant drug transporter polymorphisms earlier in the drug development process is highly desirable. In this review we examine key transporters that are important to the absorption, distribution, and excretion of a large number of drugs in clinical use. Importantly, we provide our assessment of the potential impact of known polymorphisms in such transporters and discuss whether there is sufficient evidence to incorporate these polymorphisms in the drug development process.

PMID: 27385178 [PubMed - as supplied by publisher]

Categories: Literature Watch

Causes and Consequences of Variability in Drug Transporter Activity in Pediatric Drug Therapy.

Pharmacogenomics - Fri, 2016-07-08 06:52

Causes and Consequences of Variability in Drug Transporter Activity in Pediatric Drug Therapy.

J Clin Pharmacol. 2016 Jul;56 Suppl 7:S173-S192

Authors: Rodieux F, Gotta V, Pfister M, van den Anker JN

Abstract
Drug transporters play a key role in mediating the uptake of endo- and exogenous substances into cells as well as their efflux. Therefore, variability in drug transporter activity can influence pharmaco- and toxicokinetics and be a determinant of drug safety and efficacy. In children, particularly in neonates and young infants, the contribution of tissue-specific drug transporters to drug absorption, distribution, and excretion may differ from that in adults. In this review 5 major factors and their interdependence that may influence drug transporter activity in children are discussed: developmental differences, genetic polymorphisms, pediatric comorbidities, interacting comedication, and environmental factors. Even if data are sparse, altered drug transporter activity due to those factors have been associated with clinically relevant differences in drug disposition, efficacy, and safety in pediatric patients. Single nucleotide polymorphisms in drug transporter-encoding genes were the most studied source of drug transporter variability in children. However, in the age group where drug transporter activity has been reported to differ from that in adults, namely neonates and young infants, hardly any studies have been performed. Longitudinal studies in this young population are required to investigate the age- and disease-dependent genotype-phenotype relationships and relevance of drug transporter drug-drug interactions. Physiologically based pharmacokinetic modeling approaches can integrate drug- and patient-specific parameters, including drug transporter ontogeny, and may further improve in silico predictions of pediatric-specific pharmacokinetics.

PMID: 27385174 [PubMed - as supplied by publisher]

Categories: Literature Watch

Genomics and pharmacogenomics of sepsis: so close and yet so far.

Pharmacogenomics - Fri, 2016-07-08 06:52

Genomics and pharmacogenomics of sepsis: so close and yet so far.

Crit Care. 2016;20(1):185

Authors: Russell JA

Abstract
Sapru et al. show in this issue of Critical Care that variants of thrombomodulin and the endothelial protein C receptor, but not protein C, are associated with mortality and organ dysfunction (ventilation-free and organ failure-free days) in ARDS. Hundreds of gene variants have been found prognostic in sepsis. However, none of these prognostic genomic biomarkers are used clinically. Predictive biomarker discovery (pharmacogenomics) usually follows a candidate gene approach, utilizing knowledge of drug pathways. Pharmacogenomics could be applied to enhance efficacy and safety of drugs used for treatment of sepsis (e.g., norepinephrine, epinephrine, vasopressin, and corticosteroids). Pharmacogenomics can enhance drug development in sepsis, which is very important because there is no approved drug for sepsis. Pharmacogenomics biomarkers must pass three milestones: scientific, regulatory, and commercial. Huge challenges remain but great opportunities for pharmacogenomics of sepsis are on the horizon.

PMID: 27384443 [PubMed - as supplied by publisher]

Categories: Literature Watch

Incorporation of farnesol significantly increases the efficacy of liposomal ciprofloxacin against Pseudomonas aeruginosa biofilms in vitro.

Cystic Fibrosis - Fri, 2016-07-08 06:52

Incorporation of farnesol significantly increases the efficacy of liposomal ciprofloxacin against Pseudomonas aeruginosa biofilms in vitro.

Mol Pharm. 2016 Jul 6;

Authors: Bandara HM, Herpin MJ, Kolacny D, Harb A, Romanovicz D, Smyth HD

Abstract
The challenge of eliminating Pseudomonas aeruginosa infections, such as in cystic fibrosis lungs, remains unchanged due to the rapid development of antibiotic resistance. Poor drug penetration into dense P. aeruginosa biofilms plays a vital role in ineffective clearance of the infection. Thus, the current antibiotic therapy against P. aeruginosa biofilms need to be revisited and alternative anti-biofilm strategies need to be invented. Fungal quorum sensing molecule (QSM), farnesol, appear to have detrimental effects on P. aeruginosa. Thus, this study aimed to co-deliver naturally occurring QSM farnesol, with the antibiotic ciprofloxacin as a liposomal formulation to eradicate P. aeruginosa biofilms. Four different liposomes (with ciprofloxacin and farnesol: Lcip+far, with ciprofloxacin: Lcip, with farnesol: Lfar, control: Lcon) were prepared using dehydration-rehydration method and characterized. Drug entrapment and release were evaluated by spectrometry and high performance liquid chromatography (HPLC). The efficacy of liposomes was assessed using standard biofilm assay. Liposome-treated 24h P. aeruginosa biofilms were quantitatively assessed by XTT reduction assay and crystal violet assay, qualitatively by confocal laser scanning microscopy (CLSM) and transmission electron microscopy (TEM). Ciprofloxacin release from liposomes was higher when encapsulated with farnesol (Lcip+far ) compared to Lcip (3.06% vs 1.48%) whereas farnesol release was lower when encapsulated with ciprofloxacin (Lcip+far ) compared to Lfar (1.81% vs 4.75%). The biofilm metabolism was significantly lower when treated with Lcip+far or Lcip compared to free ciprofloxacin (XTT, P<0.05). When administered as Lcip+far, the ciprofloxacin concentration required to achieve similar biofilm inhibition was 125-fold or 10-fold lower compared to free ciprofloxacin or Lcip respectively (P<0.05). CLSM and TEM confirmed predominant biofilm disruption, greater dead cell ratio and increased depth of biofilm killing when treated with Lcip+far compared to other liposomal preparations. Thus, co-delivery of farnesol and ciprofloxacin is likely to be a promising approach to battle antibiotic resistant P. aeruginosa biofilms by enhancing biofilm killing at significantly lower antibiotic doses.

PMID: 27383205 [PubMed - as supplied by publisher]

Categories: Literature Watch

Mutation at a distance caused by homopolymeric guanine repeats in Saccharomyces cerevisiae.

Systems Biology - Fri, 2016-07-08 06:52

Mutation at a distance caused by homopolymeric guanine repeats in Saccharomyces cerevisiae.

Sci Adv. 2016 May;2(5):e1501033

Authors: McDonald MJ, Yu YH, Guo JF, Chong SY, Kao CF, Leu JY

Abstract
Mutation provides the raw material from which natural selection shapes adaptations. The rate at which new mutations arise is therefore a key factor that determines the tempo and mode of evolution. However, an accurate assessment of the mutation rate of a given organism is difficult because mutation rate varies on a fine scale within a genome. A central challenge of evolutionary genetics is to determine the underlying causes of this variation. In earlier work, we had shown that repeat sequences not only are prone to a high rate of expansion and contraction but also can cause an increase in mutation rate (on the order of kilobases) of the sequence surrounding the repeat. We perform experiments that show that simple guanine repeats 13 bp (base pairs) in length or longer (G 13+ ) increase the substitution rate 4- to 18-fold in the downstream DNA sequence, and this correlates with DNA replication timing (R = 0.89). We show that G 13+ mutagenicity results from the interplay of both error-prone translesion synthesis and homologous recombination repair pathways. The mutagenic repeats that we study have the potential to be exploited for the artificial elevation of mutation rate in systems biology and synthetic biology applications.

PMID: 27386516 [PubMed - as supplied by publisher]

Categories: Literature Watch

New approaches and omics tools for mining of vaccine candidates against vector-borne diseases.

Systems Biology - Fri, 2016-07-08 06:52

New approaches and omics tools for mining of vaccine candidates against vector-borne diseases.

Mol Biosyst. 2016 Jul 7;

Authors: Kuleš J, Horvatić A, Guillemin N, Galan A, Mrljak V, Bhide M

Abstract
Vector-borne diseases (VBDs) present a major threat to human and animal health, as well as place a substantial burden on livestock production. As a way of sustainable VBD control, focus is set on vaccine development. Advances in genomics and other "omics" over the past two decades have given rise to a "third generation" of vaccines based on technologies such as reverse vaccinology, functional genomics, immunomics, structural vaccinology and the systems biology approach. The application of omics approaches is shortening the time required to develop the vaccines and increasing the probability of discovery of potential vaccine candidates. Herein, we review the development of new generation vaccines for VBDs, and discuss technological advancement and overall challenges in the vaccine development pipeline. Special emphasis is placed on the development of anti-tick vaccines that can quell both vectors and pathogens.

PMID: 27384976 [PubMed - as supplied by publisher]

Categories: Literature Watch

Rationale and design of the PREFERS (Preserved and Reduced Ejection Fraction Epidemiological Regional Study) Stockholm heart failure study: an epidemiological regional study in Stockholm county of 2.1 million inhabitants.

Systems Biology - Fri, 2016-07-08 06:52

Rationale and design of the PREFERS (Preserved and Reduced Ejection Fraction Epidemiological Regional Study) Stockholm heart failure study: an epidemiological regional study in Stockholm county of 2.1 million inhabitants.

Eur J Heart Fail. 2016 Jul 7;

Authors: Linde C, Eriksson MJ, Hage C, Wallén H, Persson B, Corbascio M, Lundeberg J, Maret E, Ugander M, Persson H, Stockholm County/Karolinska Institutet 4D heart failure investigators

Abstract
AIMS: Heart failure (HF) with preserved (HFpEF) or reduced (HFrEF) ejection fraction is associated with poor prognosis and quality of life. While the incidence of HFrEF is declining and HF treatment is effective, HFpEF is increasing, with no established therapy. PREFERS Stockholm is an epidemiological study with the aim of improving clinical care and research in HF and to find new targets for drug treatment in HFpEF ( https://internwebben.ki.se/sites/default/files/20150605_4d_research_appendix_final.pdf).
METHODS: Patients with new-onset HF (n = 2000) will be characterized at baseline and after 1-year follow-up by standardized protocols for clinical evaluation, echocardiography, and ECG. In one subset undergoing elective coronary bypass surgery (n = 100) and classified according to LV function, myocardial biopsies will be collected during surgery, and cardiac magnetic resonance (CMR) imaging will be performed at baseline and after 1 year. Blood and tissue samples will be stored in a biobank. We will characterize and compare new-onset HFpEF and HFrEF patients regarding clinical findings and cardiac imaging, genomics, proteomics, and transcriptomics from blood and cardiac biopsies, and by established biomarkers of fibrosis, inflammation, haemodynamics, haemostasis, and thrombosis. The data will be explored by state-of-the-art bioinformatics methods to investigate gene expression patterns, sequence variation, DNA methylation, and post-translational modifications, and using systems biology approaches including pathway and network analysis.
CONCLUSIONS: In this epidemiological HF study with biopsy studies in a subset of patients, we aim to identify new biomarkers of disease progression and to find pathophysiological mechanisms to support explorations of new treatment regimens for HFpEF.

PMID: 27384611 [PubMed - as supplied by publisher]

Categories: Literature Watch

Neural oscillations as a signature of efficient coding in the presence of synaptic delays.

Systems Biology - Fri, 2016-07-08 06:52

Neural oscillations as a signature of efficient coding in the presence of synaptic delays.

Elife. 2016 Jul 7;5

Authors: Chalk M, Gutkin B, Denève S

Abstract
Cortical networks exhibit 'global oscillations', where neural spikes are entrained to an underlying oscillatory rhythm, but where individual neurons fire irregularly. While the network dynamics underlying global oscillations are well characterised, their function is debated. Here, we show that such global oscillations are a direct consequence of optimal efficient coding in spiking networks with synaptic delays. To avoid firing unnecessary spikes, neurons must share information about the network state. Ideally, membrane potentials should be correlated and reflect a 'prediction error' while spikes themselves are uncorrelated and occur rarely. We show that the most efficient representation is achieved when: (i) spikes are entrained to a global Gamma rhythm (implying a consistent representation of the error); but (ii) few neurons fire on each cycle (implying high efficiency), while (iii) excitation and inhibition are tightly balanced. This suggests that cortical networks exhibiting such dynamics are tuned to achieve a maximally efficient population code.

PMID: 27383272 [PubMed - as supplied by publisher]

Categories: Literature Watch

Molecular dynamics-based renement and validation with Resolution Exchange MDFF for sub-5 Å cryo-electron microscopy maps.

Systems Biology - Fri, 2016-07-08 06:52

Molecular dynamics-based renement and validation with Resolution Exchange MDFF for sub-5 Å cryo-electron microscopy maps.

Elife. 2016 Jul 7;5

Authors: Singharoy A, Teo I, McGreevy R, Stone JE, Zhao J, Schulten K

Abstract
Two structure determination methods, based on the molecular dynamics flexible fitting (MDFF) paradigm, are presented that resolve sub-5-Å cryo-electron microscopy (EM) maps with either single structures or ensembles of such structures. The methods, denoted cascade MDFF and resolution exchange MDFF, sequentially re-refine a search model against a series of maps of progressively higher resolutions, which ends with the original experimental resolution. Application of sequential re-refinement enables MDFF to achieve a convergence radius of ~25Å demonstrated with the accurate modeling of β-galactosidase and TRPV1 proteins at 3.2Å and 3.4Å resolution. The MDFF refinements uniquely offer map-model validation and B-factor determination criteria based on the inherent dynamics of the respective macromolecules studied, captured employing local root mean square fluctuations. The MDFF tools are made available to researchers through an easy-to-use and cost-effective cloud computing resource on Amazon Web Services.

PMID: 27383269 [PubMed - as supplied by publisher]

Categories: Literature Watch

Metabolic network rewiring of propionate flux compensates vitamin B12 deficiency in C. elegans.

Systems Biology - Fri, 2016-07-08 06:52

Metabolic network rewiring of propionate flux compensates vitamin B12 deficiency in C. elegans.

Elife. 2016 Jul 6;5

Authors: Walhout AJ, Watson E, Olin-Sandoval V, Hoy MJ, Li CH, Louisse T, Yao V, Mori A, Holdorf AD, Troyanskaya OG, Ralser M

Abstract
Metabolic network rewiring is the rerouting of metabolism through the use of alternate enzymes to adjust pathway flux and accomplish specific anabolic or catabolic objectives. Here, we report the first characterization of two parallel pathways for the breakdown of the short chain fatty acid propionate in Caenorhabditis elegans. Using genetic interaction mapping, gene co-expression analysis, pathway intermediate quantification and carbon tracing, we uncover a vitamin B12-independent propionate breakdown shunt that is transcriptionally activated on vitamin B12 deficient diets, or under genetic conditions mimicking the human diseases propionic- and methylmalonic acidemia, in which the canonical B12-dependent propionate breakdown pathway is blocked. Our study presents the first example of transcriptional vitamin-directed metabolic network rewiring to promote survival under vitamin deficiency. The ability to reroute propionate breakdown according to B12 availability may provide C. elegans with metabolic plasticity and thus a selective advantage on different diets in the wild.

PMID: 27383050 [PubMed - as supplied by publisher]

Categories: Literature Watch

Computing symmetrical strength of N-grams: a two pass filtering approach in automatic classification of text documents.

Drug-induced Adverse Events - Fri, 2016-07-08 06:52

Computing symmetrical strength of N-grams: a two pass filtering approach in automatic classification of text documents.

Springerplus. 2016;5(1):942

Authors: Agnihotri D, Verma K, Tripathi P

Abstract
The contiguous sequences of the terms (N-grams) in the documents are symmetrically distributed among different classes. The symmetrical distribution of the N-Grams raises uncertainty in the belongings of the N-Grams towards the class. In this paper, we focused on the selection of most discriminating N-Grams by reducing the effects of symmetrical distribution. In this context, a new text feature selection method named as the symmetrical strength of the N-Grams (SSNG) is proposed using a two pass filtering based feature selection (TPF) approach. Initially, in the first pass of the TPF, the SSNG method chooses various informative N-Grams from the entire extracted N-Grams of the corpus. Subsequently, in the second pass the well-known Chi Square (χ(2)) method is being used to select few most informative N-Grams. Further, to classify the documents the two standard classifiers Multinomial Naive Bayes and Linear Support Vector Machine have been applied on the ten standard text data sets. In most of the datasets, the experimental results state the performance and success rate of SSNG method using TPF approach is superior to the state-of-the-art methods viz. Mutual Information, Information Gain, Odds Ratio, Discriminating Feature Selection and χ(2).

PMID: 27386386 [PubMed - as supplied by publisher]

Categories: Literature Watch

("orphan disease" OR "rare disease" OR "orphan diseases" OR "rare diseases"); +17 new citations

Orphan or Rare Diseases - Thu, 2016-07-07 06:20

17 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

("orphan disease" OR "rare disease" OR "orphan diseases" OR "rare diseases")

These pubmed results were generated on 2016/07/07

PubMed comprises more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Categories: Literature Watch

"Cystic Fibrosis"; +9 new citations

Cystic Fibrosis - Thu, 2016-07-07 06:20

9 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

"Cystic Fibrosis"

These pubmed results were generated on 2016/07/07

PubMed comprises more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Categories: Literature Watch

Could the FDA-approved anti-HIV PR inhibitors be promising anticancer agents? An answer from enhanced docking approach and molecular dynamics analyses.

Drug Repositioning - Thu, 2016-07-07 06:20
Related Articles

Could the FDA-approved anti-HIV PR inhibitors be promising anticancer agents? An answer from enhanced docking approach and molecular dynamics analyses.

Drug Des Devel Ther. 2015;9:6055-65

Authors: Arodola OA, Soliman ME

Abstract
Based on experimental data, the anticancer activity of nelfinavir (NFV), a US Food and Drug Administration (FDA)-approved HIV-1 protease inhibitor (PI), was reported. Nevertheless, the mechanism of action of NFV is yet to be verified. It was hypothesized that the anticancer activity of NFV is due to its inhibitory effect on heat shock protein 90 (Hsp90), a promising target for anticancer therapy. Such findings prompted us to investigate the potential anticancer activity of all other FDA-approved HIV-1 PIs against human Hsp90. To accomplish this, "loop docking" - an enhanced in-house developed molecular docking approach - followed by molecular dynamic simulations and postdynamic analyses were performed to elaborate on the binding mechanism and relative binding affinities of nine FDA-approved HIV-1 PIs against human Hsp90. Due to the lack of the X-ray crystal structure of human Hsp90, homology modeling was performed to create its 3D structure for subsequent simulations. Results showed that NFV has better binding affinity (ΔG =-9.2 kcal/mol) when compared with other PIs: this is in a reasonable accordance with the experimental data (IC50 3.1 μM). Indinavir, saquinavir, and ritonavir have close binding affinity to NFV (ΔG =-9.0, -8.6, and -8.5 kcal/mol, respectively). Per-residue interaction energy decomposition analysis showed that hydrophobic interaction (most importantly with Val534 and Met602) played the most predominant role in drug binding. To further validate the docking outcome, 5 ns molecular dynamic simulations were performed in order to assess the stability of the docked complexes. To our knowledge, this is the first account of detailed computational investigations aimed to investigate the potential anticancer activity and the binding mechanism of the FDA-approved HIV PIs binding to human Hsp90. Information gained from this study should also provide a route map toward the design, optimization, and further experimental investigation of potential derivatives of PIs to treat HER2+ breast cancer.

PMID: 26622167 [PubMed - indexed for MEDLINE]

Categories: Literature Watch

Re-engineering a neuroprotective, clinical drug as a procognitive agent with high in vivo potency and with GABAA potentiating activity for use in dementia.

Drug Repositioning - Thu, 2016-07-07 06:20
Related Articles

Re-engineering a neuroprotective, clinical drug as a procognitive agent with high in vivo potency and with GABAA potentiating activity for use in dementia.

BMC Neurosci. 2015;16:67

Authors: Luo J, Lee SH, VandeVrede L, Qin Z, Piyankarage S, Tavassoli E, Asghodom RT, Ben Aissa M, Fà M, Arancio O, Yue L, Pepperberg DR, Thatcher GR

Abstract
BACKGROUND: Synaptic dysfunction is a key event in pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD) where synapse loss pathologically correlates with cognitive decline and dementia. Although evidence suggests that aberrant protein production and aggregation are the causative factors in familial subsets of such diseases, drugs singularly targeting these hallmark proteins, such as amyloid-β, have failed in late stage clinical trials. Therefore, to provide a successful disease-modifying compound and address synaptic dysfunction and memory loss in AD and mixed pathology dementia, we repurposed a clinically proven drug, CMZ, with neuroprotective and anti-inflammatory properties via addition of nitric oxide (NO) and cGMP signaling property.
RESULTS: The novel compound, NMZ, was shown to retain the GABAA potentiating actions of CMZ in vitro and sedative activity in vivo. Importantly, NMZ restored LTP in hippocampal slices from AD transgenic mice, whereas CMZ was without effect. NMZ reversed amnestic blockade of acetylcholine receptors by scopolamine as well as NMDA receptor blockade by a benzodiazepine and a NO synthase inhibitor in the step-through passive avoidance (STPA) test of learning and working memory. A PK/PD relationship was developed based on STPA analysis coupled with pharmacokinetic measures of drug levels in the brain: at 1 nM concentration in brain and plasma, NMZ was able to restore memory consolidation in mice.
CONCLUSION: Our findings show that NMZ embodies a promising pharmacological approach targeting synaptic dysfunction and opens new avenues for neuroprotective intervention strategies in mixed pathology AD, neurodegeneration, and dementia.

PMID: 26480871 [PubMed - indexed for MEDLINE]

Categories: Literature Watch

Repurposing Non-Antimicrobial Drugs and Clinical Molecules to Treat Bacterial Infections.

Drug Repositioning - Thu, 2016-07-07 06:20
Related Articles

Repurposing Non-Antimicrobial Drugs and Clinical Molecules to Treat Bacterial Infections.

Curr Pharm Des. 2015;21(28):4106-11

Authors: Younis W, Thangamani S, Seleem MN

Abstract
There is a pressing need to develop novel antimicrobials to circumvent the scourge of antimicrobial resistance. The objective of this study is to identify non-antibiotic drugs with potent antimicrobial activity, within an applicable clinical range. A library, containing 727 FDA approved drugs and small molecules, was screened against ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter cloacae). Drugs that showed antimicrobial activity in an applicable clinical range were further tested in vitro and in vivo in an infected mouse model. The initial screening identified 24 non-antibiotic drugs and clinical molecules active against Gram-positive pathogens including methicillin- resistant S. aureus (MRSA) and vancomycin-resistant enterococcus (VRE) isolates. Two non-antibiotic drugs showed activity against Gram-negative pathogens. Among the active non-antibiotic drugs, only ebselen (EB) and 5-fluoro-2'-deoxyuridine (FdUrd), showed bactericidal activity, in an applicable clinical range, against multi-drug-resistant Staphylococcus isolates including MRSA, vancomycin-resistant S. aureus (VRSA), and vancomycin-intermediate S. aureus (VISA). The minimum inhibitory concentration at which 90% of clinical isolates of S. aureus were inhibited (MIC90) was found to be 0.25 and 0.0039mg/L for EB and FdUrd, respectively. Treatment with EB orally significantly increased mice survival in a lethal model of septicemic MRSA infection by (60%) compared to that of control. FdUrd oral and intraperitoneal treatment significantly enhanced mouse survival by 60% and 100%, respectively. These data encourage screening and repurposing of non-antibiotic drugs and clinical molecules to treat multidrug-resistant bacterial infections.

PMID: 25961308 [PubMed - indexed for MEDLINE]

Categories: Literature Watch

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