The Relevance of Integrating CYP2C19 Phenoconversion Effects into Clinical Pharmacogenetics

INTRODUCTION

CYP2D6 and CYP2C19 functional status as defined by genotype is modulated by phenoconversion (PC) due to pharmacokinetic interactions. As of today, there is no data on the effect size of PC for CYP2C19 functional status. The primary aim of this study was to investigate the impact of PC on CYP2C19 functional status.

METHODS

Two patient cohorts (total n=316; 44.2±15.4 years) were investigated for the functional enzyme status of CYP2C19 applying two different correction methods (PCBousman, PCHahn&Roll) as well as serum concentration and metabolite-to-parent ratio of venlafaxine, amitriptyline, mirtazapine, sertraline, escitalopram, risperidone, and quetiapine.

RESULTS

There was a decrease in the number of normal metabolizers of CYP2C19 and an increase in the number of poor metabolizers. When controlled for age, sex, and, in the case of amitriptyline, venlafaxine, and risperidone, CYP2D6 functional enzyme status, an association was observed between the CYP2C19 phenotype/functional enzyme status and serum concentration of amitriptyline, sertraline, and escitalopram.

DISCUSSION

PC of CYP2C19 changes phenotypes but does not improve correlations with serum concentrations. However, only a limited number of patients received perturbators of CYP2C19. Studies with large numbers of patients are still lacking, and thus, it cannot be decided if there are minor differences and which method of correction to use. For the time being, PC is relevant in individual patients treated with CYP2C19-affecting drugs, for example, esomeprazole. To ensure adequate serum concentrations in these patients, this study suggests the use of therapeutic drug monitoring.

Effect of CYP2D6 pharmacogenetic phenotype and phenoconversion on serum concentrations of antidepressants and antipsychotics: a retrospective cohort study

BACKGROUND

Pharmacogenetics (PGx), especially in regard to CYP2D6, is gaining more importance in routine clinical settings. Including phenoconversion effects (PC) in result interpretation could maximize its potential benefits. However, studies on genetics of pharmacokinetic genes including the functional enzyme status are lacking.

AIM

The retrospective analyses of clinical routine data aimed to investigating how the CYP2D6 functional enzyme status affects serum concentrations and metabolite-to-parent ratios of seven common psychotropic drugs and allows an evaluation of the relevance of this information for patient care.

METHOD

Two patient cohorts (total n = 316; 44.2 ± 15.4 years) were investigated for the CYP2D6 functional enzyme status and its associations with drug exposure and metabolism of venlafaxine, amitriptyline, mirtazapine, sertraline, escitalopram, risperidone and quetiapine.

RESULTS

We found an increase in intermediate and poor metabolizers, as well as a decrease in normal metabolizers of CYP2D6 when including PC. Moreover, we found associations between amitriptyline exposure with the phenoconversion-corrected activity score of CYP2D6 (Spearman correlation; p = 0.03), and risperidone exposure with CYP2D6 functional enzyme status (Kruskal-Wallis test; p = 0.01), as well as between metabolite-to-parent ratio of venlafaxine and risperidone with CYP2D6 functional enzyme status (Kruskal-Wallis test; p < 0.001; p = 0.05).

CONCLUSION

The data stress the relevance of PC-informed PGx in psychopharmacological treatment and suggest that PC should be included in PGx result interpretation when PGx is implemented in routine clinical care, especially before initiating amitriptyline- or risperidone-treatment, to start with a dose adequate to the respective CYP2D6 functional enzyme status. Moreover, PGx and therapeutic drug monitoring should be used complementary but not alternatively.

[Barriers for Implementation of PGx Testing in Psychiatric Hospitals in Germany: Results of the FACT-PGx Study]

OBJECTIVE

The FACT-PGx study was conducted to analyze barriers to implementation of pharmacogenetic testing in psychiatric hospitals in Germany and to propose solutions for its faster and easier implementation in all hospitals.

METHODS

104 patients (50% female) were genotyped and participated in the study. 67 completed a survey. To analyze the correlation between continuous data (age) of the survey, the wilcoxon rank test and for categorial data (education level, history of treatment and episodes), t-test was used.

RESULTS

No patient declined to be genotyped. 99% believed that genotyping could help to shorten their hospital stay. Patients >40 years of age and with higher educational levels were willing to pay for the PGx (p=0.009). On average, patients were willing to pay 117.42€ +/-140.49€ and to wait 15.83+/- 8.92 days for the results. Processes differed significantly between routine laboratory screening and PGx testing which could be a barrier for implementation.

CONCLUSION

Patients are not barriers to but enablers of an implementation of PGx. New process flows can be barriers, but can be overcome by optimization.

Incidence and presentation of new-onset type 1 diabetes in children and adolescents from Germany during the COVID-19 pandemic 2020 and 2021: Current data from the DPV Registry

AIMS

To determine whether the incidence of type 1 diabetes mellitus (T1D), autoantibody-negative diabetes, and diabetic ketoacidosis (DKA) at diabetes onset in 2020 and 2021 changed when compared to long-standing trends.

METHODS

Our study is based on diabetes manifestation data of the 0.5-<18-year-old children/adolescents from the German multicenter Diabetes Prospective Follow-up Registry. Based on long-term pre-pandemic trends from 2011 to 2019, we estimated adjusted incidence rate ratios (IRR) for T1D and DKA, and prevalence rate ratios (PRR) regarding autoantibody status with 95 % confidence intervals (CI) for the years 2020 and 2021 (observed versus predicted rates), using multivariable negative binomial or beta-binomial regression, respectively.

RESULTS

We analyzed data of 30,840 children and adolescents with new-onset T1D. The observed incidences were significantly higher than the predicted incidences (IRR₂₀₂₀ 1.13 [1.08-1.19]; IRR₂₀₂₁ 1.20 [1.15-1.26]). The prevalence of autoantibody-negative diabetes did not change (PRR₂₀₂₀ 0.91 [0.75-1.10]; PRR₂₀₂₁ 1.03 [0.86-1.24]). The incidence of DKA during the pandemic was higher than predicted (IRR₂₀₂₀ 1.34 [1.23-1.46]; IRR₂₀₂₁ 1.37 [1.26-1.49]).

CONCLUSIONS

An increase in the incidences of T1D and DKA, but not of autoantibody-negative diabetes was observed during both pandemic years. Further monitoring and efforts for DKA prevention at onset are necessary.

Prescription Advice Based on Data of Drug-Drug-Gene Interaction of Patients with Polypharmacy

Purpose

Pharmacogenetic counselling is a complex task and requires the efforts of an interdisciplinary team, which cannot be implemented in most cases. Therefore, simple rules could help to minimize the risk of medications incompatible with each other or with frequent genetic variants.

Patients and Methods

One hundred and eighty-four multi-morbid Caucasian patients suffering from side effects or inefficient therapy were enrolled and genotyped. Their medication was analyzed by a team of specialists using Drug-PIN^® (medication support system) and individual recommendations for 34 drug classes were generated.

Results

In each of the critical drug classes, 50% of the drugs cannot be recommended to be prescribed in typical drug cocktails. PPIs and SSRI/SNRIs represent the most critical drug classes without showing a single favorable drug. Among the well-tolerated drugs (not recommended for less than 5% of the patients) are metamizole, celecoxib, olmesartan and famotidine. For each drug class, a ranking of active ingredients according to their suitability is presented.

Conclusion

Genotyping and its profound analysis are not available in many settings today. The consideration of frequent alterations of metabolic elimination routes and drug–drug–gene interactions by using simple rankings can help to avoid many incompatibilities, side effects and inefficient therapies.

SuperTCM: A biocultural database combining biological pathways and historical linguistic data of Chinese Materia Medica for drug development

AIM OF THE STUDY

Botanicals used in Traditional Chinese Medicine (TCM) are a rich source for drug discovery and provide models for multi-component drug development. To facilitate the studies of the actions of TCM drugs and expand their applications, a comprehensive database is urgently required.

METHODS

One online resource connects all the relevant data from multiple scientific sources and languages. Drug information from published TCM databases and the official Chinese Pharmacopoeia as well as specialized meta-websites such as Kew's Medicinal Plant Names Service was integrated on a higher level.

RESULTS

Our database, SuperTCM, covers the aspects of TCM derived from medicinal plants, encompassing pharmacological recipes up to chemical compounds. It provides the information for 6516 TCM drugs (or "herbs") with 5372 botanical species, 55,772 active ingredients against 543 targets in 254 KEGG pathways associated with 8634 diseases. SuperTCM is freely available at http://tcm.charite.de/supertcm.

[Pharmaceutical Innovations: Superior Position of the USA and Weaknesses of German Research]

The innovative strength of research performance is often measured in terms of inputs such as research funds or outputs such as patent applications. We present a novel indicator of pharmaceutical innovativeness that focuses on global medical breakthroughs and associated patents. According to this indicator, US companies account for 55 % of global medical breakthroughs from 2010 to 2019, and their German competitors account for about 9 %. In terms of underlying anchor patents, the dominance of the US is even larger, at 62 %, while only 7 % of anchor patents come from Germany. US universities hold 3.8 % of all anchor patents; German universities hold none. The weakness of German universities cannot be compensated by German non-university research institutes.

Individualized Drugs' Selection by Evaluation of Drug Properties, Pharmacogenomics and Clinical Parameters: Performance of a Bioinformatic Tool Compared to a Clinically Established Counselling Process

Purpose

Inefficacy and safety concerns are main medications’ problems, especially in the case of poly-therapies, when drug–drug interactions may alter the expected drug disposition. Ongoing efforts are aimed to establish drug selection processes aimed to preemptive evaluation of a plethora of factors affecting patient’s specific drug response, including pharmacogenomic markers, in order to minimize prescription of improper medications. In previous years, we established at the University Hospital Sant’Andrea of Rome, Italy, a Precision Medicine Service based on a multi-disciplinary experts’ team. The team is in charge to produce a drug therapy counselling report, including pharmacogenomic, pharmacokinetic and pharmacodynamic considerations. In this study, we aimed to evaluate the performance of this established “manual” process of therapy selection with a novel bioinformatic tool, the Drug-PIN system.

Patients and Methods

A total of 200 patients diagnosed with Major Depressive Disorders or a depressive episode in Bipolar Disorder, with at least three previous failed treatments, who underwent pharmacogenomic profiling and therapy counselling in the Sant’Andrea Hospital from 2017 to 2020. The baseline poly-therapy of these patients was re-evaluated and optimized by Drug-PIN. Results of the Drug-PIN poly-therapy evaluation/optimization were compared with the results of the original poly-therapy evaluation/optimization by therapy counselling. To compare the results between the two processes, the risk associated with each poly-therapy was classified as low, moderate, or high.

Results

The number of baseline poly-therapies classified in low-, moderate- or high-risk did not change significantly between manual system or Drug-PIN system. As the counselling process, also the Drug-PIN system produces a significant decrease in the predicted treatment-associated risk.

Conclusion

Drug-PIN substantially replicates the output of the counselling process, allowing a substantial reduction in the time needed for therapy evaluation. Availability of an effective bioinformatic tool for proper drug selection is expected to exponentially increase the actuation of targeted therapy strategies.

PROMISCUOUS 2.0: a resource for drug-repositioning

The development of new drugs for diseases is a time-consuming, costly and risky process. In recent years, many drugs could be approved for other indications. This repurposing process allows to effectively reduce development costs, time and, ultimately, save patients’ lives. During the ongoing COVID-19 pandemic, drug repositioning has gained widespread attention as a fast opportunity to find potential treatments against the newly emerging disease. In order to expand this field to researchers with varying levels of experience, we made an effort to open it to all users (meaning novices as well as experts in cheminformatics) by significantly improving the entry-level user experience. The browsing functionality can be used as a global entry point to collect further information with regards to small molecules (∼1 million), side-effects (∼110 000) or drug-target interactions (∼3 million). The drug-repositioning tab for small molecules will also suggest possible drug-repositioning opportunities to the user by using structural similarity measurements for small molecules using two different approaches. Additionally, using information from the Promiscuous 2.0 Database, lists of candidate drugs for given indications were precomputed, including a section dedicated to potential treatments for COVID-19. All the information is interconnected by a dynamic network-based visualization to identify new indications for available compounds. Promiscuous 2.0 is unique in its functionality and is publicly available at http://bioinformatics.charite.de/promiscuous2.

Repetitive enhancement of serum BDNF subsequent to continuation ECT

INTRODUCTION

Continuation electroconvulsive therapy (c-ECT) is highly effective for the prevention of depressive symptom relapse. There is a lack of understanding, about how c-ECT works in humans, particularly with regard to its effects on brain derived neurotrophic factor (BDNF) concentrations. Here, we aimed to close a gap in the literature by evaluating BDNF levels in patients receiving c-ECT.

METHODS

We included 13 patients with either unipolar or bipolar depression (mean age ± SD: 55.5 ± 17.1; f/m: 10/3; unipolar/bipolar: 10/3) who received between one and four c-ECT (average per patient: 2.8). Serum BDNF (sBDNF) levels were assessed before and after each c-ECT sessions. Clinical assessments were also administered both before and after treatment.

RESULTS

Our analysis revealed a significant increase in sBDNF after each treatment (c-ECT 1-3: P < 0.001, c-ECT 4: P = 0.018). The application of multiple c-ECT treatments was not, however, associated with further sBDNF enhancements. Psychometric scores were not significantly altered following c-ECT.

DISCUSSION

An increase in sBDNF concentrations subsequent to c-ECT parallel data from the animal literature, which has linked regularly applied electrical stimulation to neuroplastic processes. This finding suggests a relationship between ECT-induced sBDNF concentrations and (sustained) remission status, considering a stable clinical condition across c-ECT.

Volumetric tissue reduction in radiofrequency surgery of the tongue base

OBJECTIVES:

Radiofrequency surgery is a minimally invasive technique for the treatment of the tongue base in sleep-disordered breathing. The aim of this study was to evaluate the changes in upper airway anatomy induced by radiofrequency surgery with MRI.

STUDY DESIGN AND SETTING:

10 patients with sleep-disordered breathing were treated with radiofrequency surgery at tongue base. MRI measurements were performed before and after surgery with the help of a recently published protocol.

RESULTS:

The mean total number of energy delivered per patient was 4750 ± 1641 Joule. Relevant changes could be observed neither for tongue volume or dimension nor for retrolingual space.

CONCLUSIONS:

Changes in upper airway anatomy could not be demonstrated. The effects of radiofrequency surgery of the tongue base may more likely be a result of changes in upper airway collapsibility.

SIGNIFICANCE:

Functional effects of surgical interventions in sleep-disordered breathing should be considered in addition to mechanistic concepts alone.

Comparison of Conservative and Surgical Therapy Concepts for Synechia of the Labia in Pre-Pubertal Girls

Introduction: The aim of this study was to evaluate the primary and secondary therapeutic successes of different therapy schemes for the treatment of synechia of the labia in pre-pubertal girls. Materials and Methods: The treatment courses of 47 pre-pubertal girls who were treated between February 2007 and February 2013 in the special outpatient clinic for paediatric gynaecology of a department for gynaecology at a German university hospital and for whom information on the course of the disease was available for at least the six months following end of the treatment. 23 of these children were treated with a topical estriol therapy (treatment group A). For 24 of the girls a manual separation of the adhering labia minora was undertaken (treatment group B). Statistical evaluation was performed using the χ² test, Fischer's exact test and the Mann-Whitney U test. Results: For 18 of the 23 (80 %) girls in treatment group A topical estriol therapy alone led to a resolution of the synechia. Five of these 23 children (20 %) required a secondary manual separation. All girls for whom treatment was not successful were under 5 years of age. For all 24 girls (100 %) of treatment group B the primary manual separation was performed with success. The recurrence rates after ≥ 6 months in cases with identical after-care did not differ between the two treatment groups (treatment group A: 34 %, treatment group B: 33 %, χ² test: p = 0.853). 16 of the 17 recurrences occurred ≥ 3 months after the end of the therapy. Conclusion: Our results show that for children < 5 years of age a 4-week topical therapy with estriol is a promising therapy option for synechia of the labia that is less of a burden for the family situation. Especially for girls ≥ 5 years of age, primary therapy fails in up to 20 % of the cases. Primary manual separation represents a more effective therapeutic option. Irrespective of the treatment applied, a recurrence after ≥ 3 must be expected in one-third of the treated girls.

Assessment of mature serum brain-derived neurotrophic factor (BDNF) is not superior to total serum BDNF in prediction of antidepressant treatment outcome

Background

Serum BDNF levels are decreased in major depressive disorder (MDD) and tend to normalize under antidepressant treatment, serving as a treatment outcome predictor. BDNF is initially synthetized as precursor protein proBDNF and is cleaved to mature BDNF (mBDNF) while only the latter exerts neurotrophic activity.

Aim

The aim was to explore if a specific enzyme-linked immunosorbent assay (ELISA) kit for mBDNF in serum would be superior to the unspecific assessment of total serum BDNF in predicting treatment response in MDD.

Methods

Twenty-five patients with MDD underwent standardized treatment with duloxetine. Severity of depression was measured by Hamilton Depression Rating Scale (HDRS) at baseline (BL), after one (W1), two (W2) and six weeks (W6) of treatment. Treatment response was defined as a HDRS ≥ 50% reduction of BL score at W6. mBDNF and total BDNF serum levels were determined at BL, W1 and W2.

Results

A high and stable correlation was found between mBDNF and total BDNF serum levels over all measurements. The predictive value of mBDNF BL levels and mBDNFΔW1 to response was similar to that of total BDNF BL and total BDNFΔW1. The assessment of serum mBDNF was not superior to total BDNF in prediction of treatment outcome.

Conclusions

Not only baseline total BDNF but also mBDNF is predictive to treatment outcome. The later might represent the main player in this respect, which supports the idea of a functional link between neuroplasticity and MDD.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

[Phthiriasis, the mysterious lousy disease of antiquity. Fact or fiction?]

The lousy disease (phthiriasis) and its potentially deadly consequences is well attested from antiquity until the 19th century. Intensely itching, vesicular or tumorous skin lesions defile the body and release swarms of insects spontaneously or after incision. Several well-known persons from antiquity and the early modern period are supposed to have died of the lousy disease. Both classicists and physicians have questioned the credibility of said accounts. By means of our interdisciplinary approach based on an analysis of different descriptions of the lousy disease from antiquity to the 19th century, this paper will present strong arguments for the existence of a potentially lethal form of phthiriasis. In contrast to its name, the lousy disease was most likely caused by a species of mites, similar to the one causing cystic subepidermal tumors in birds.

Calcium channel blockers and dementia

Degenerative dementia is mainly caused by Alzheimer's disease and/or cerebrovascular abnormalities. Disturbance of the intracellular calcium homeostasis is central to the pathophysiology of neurodegeneration. In Alzheimer's disease, enhanced calcium load may be brought about by extracellular accumulation of amyloid-β. Recent studies suggest that soluble forms facilitate influx through calcium-conducting ion channels in the plasma membrane, leading to excitotoxic neurodegeneration. Calcium channel blockade attenuates amyloid-β-induced neuronal decline in vitro and is neuroprotective in animal models. Vascular dementia, on the other hand, is caused by cerebral hypoperfusion and may benefit from calcium channel blockade due to relaxation of the cerebral vasculature. Several calcium channel blockers have been tested in clinical trials of dementia and the outcome is heterogeneous. Nimodipine as well as nilvadipine prevent cognitive decline in some trials, whereas other calcium channel blockers failed. In trials with a positive outcome, BP reduction did not seem to play a role in preventing dementia, indicating a direct protecting effect on neurons. An optimization of calcium channel blockers for the treatment of dementia may involve an increase of selectivity for presynaptic calcium channels and an improvement of the affinity to the inactivated state. Novel low molecular weight compounds suitable for proof-of-concept studies are now available.

Inosose-Flüssigkristalle / Inosose Liquid Crystals

Six S,S-dialkyl acetals 2a-f of inosose (1), tripodal in structure, have been synthesized, characterized and investigated by optical microscopy and differential scanning calorimetry (d.s.c.). The four S,S-acetals 2c-f with sufficiently long alkyl chains are thermotropic liquid crystalline; 2 e and 2 f are even dithermomesomorphic. Each of these four inosose derivatives 2c-f exhibits monotropically a most likely cubic mesophase (MI); in addition 2e and 2f show enantiotropically a hexagonal mesophase (Hx) with a non-covalent, supramolecular H-bridge architecture. Whereas the nature of the optically isotropic mesophase MI needs further clarification the stable high temperature mesophase Hx of 2 e and 2 f has been established by a miscibility test using a sugar S,S-dialkyl acetal also tripodal in structure and with a Hx phase proved by X-ray diffraction, but in contrast to 2 with an acyclic hydrophilic part. Similarities of structural features between the Hx-phases of 2e and 2f as well as of other thermotropic and lyotropic liquid crystal systems are discussed briefly.

SuperTarget goes quantitative: update on drug-target interactions

There are at least two good reasons for the on-going interest in drug–target interactions: first, drug-effects can only be fully understood by considering a complex network of interactions to multiple targets (so-called off-target effects) including metabolic and signaling pathways; second, it is crucial to consider drug-target-pathway relations for the identification of novel targets for drug development. To address this on-going need, we have developed a web-based data warehouse named SuperTarget, which integrates drug-related information associated with medical indications, adverse drug effects, drug metabolism, pathways and Gene Ontology (GO) terms for target proteins. At present, the updated database contains >6000 target proteins, which are annotated with >330 000 relations to 196 000 compounds (including approved drugs); the vast majority of interactions include binding affinities and pointers to the respective literature sources. The user interface provides tools for drug screening and target similarity inclusion. A query interface enables the user to pose complex queries, for example, to find drugs that target a certain pathway, interacting drugs that are metabolized by the same cytochrome P450 or drugs that target proteins within a certain affinity range. SuperTarget is available at http://bioinformatics.charite.de/supertarget.

Pilot study of the application of magnetic bead protein profiling to the study of biomarkers in addiction research

OBJECTIVES

Proteomic technologies based on mass spectrometry are increasingly used as a valuable tool in clinical research allowing high-throughput protein and peptide profiling to be undertaken. Whilst previous research has focussed the application of this novel technology on the study of patients with disorders compared to comparable individuals from the healthy population, this current study seeks to determine the effect of successful treatment for alcoholism on the serum protein profile obtained.

METHODS

Serum samples were collected from patients after initial treatment for alcohol abuse and also 6 months after treatment. The serum samples were prepared for analysis using reverse phase magnetic bead fractionation and the resulting peptides analysed by matrix assisted laser desorption ionisation time-of-flight (MALDI-ToF) mass spectrometry.

RESULTS

Whilst the majority of the peptides detected by this approach exhibited constant levels between the two time points, three peptides were elevated at the 6-month time point compared to the initial sampling.

CONCLUSIONS

Whilst disorders with very clear biological causes (such as cancer) exhibit significantly different peptide profiles, psychiatric disorders such as alcohol addiction which are multifactorial show less obvious changes. Despite this the two groups of samples could statistically be distinguished by certain peptides expression levels.

Association genetics of carbon isotope discrimination, height and foliar nitrogen in a natural population of Pinus taeda L

Loblolly pine, Pinus taeda L., is one of the most widely planted, commercially and ecologically important tree species in North America. We took an association genetics approach, using an unimproved population of 380 clonally replicated unrelated trees, to test 3,938 single nucleotide polymorphisms (SNPs) in as many genes for association with phenotypic variation in carbon isotope discrimination, foliar nitrogen concentration and total tree height after two growing seasons. Best linear unbiased prediction (BLUP) was used with a spatial adjustment to remove environmental variation from phenotypic data derived from a common garden experiment. After correction for multiple testing, a total of 14 SNPs were associated with the traits of carbon isotope discrimination (n = 7), height (n = 1) and foliar nitrogen concentration (n = 6) using 380 clones. Tails of the population phenotypic distribution were compared for allele frequency differences, revealing 10 SNPs with allele frequency in at least one tail significantly different from the overall population. Eight associated SNPs were in sequences similar to known genes, such as an AP2 transcription factor related to carbon isotope discrimination and glutamate decarboxylase associated with foliar nitrogen concentration, and others were from unknown genes without homologs in Arabidopsis.

CancerResource: a comprehensive database of cancer-relevant proteins and compound interactions supported by experimental knowledge

During the development of methods for cancer diagnosis and treatment, a vast amount of information is generated. Novel cancer target proteins have been identified and many compounds that activate or inhibit cancer-relevant target genes have been developed. This knowledge is based on an immense number of experimentally validated compound–target interactions in the literature, and excerpts from literature text mining are spread over numerous data sources. Our own analysis shows that the overlap between important existing repositories such as Comparative Toxicogenomics Database (CTD), Therapeutic Target Database (TTD), Pharmacogenomics Knowledge Base (PharmGKB) and DrugBank as well as between our own literature mining for cancer-annotated entries is surprisingly small. In order to provide an easy overview of interaction data, it is essential to integrate this information into a single, comprehensive data repository. Here, we present CancerResource, a database that integrates cancer-relevant relationships of compounds and targets from (i) our own literature mining and (ii) external resources complemented with (iii) essential experimental and supporting information on genes and cellular effects. In order to facilitate an overview of existing and supporting information, a series of novel information connections have been established. CancerResource addresses the spectrum of research on compound–target interactions in natural sciences as well as in individualized medicine; CancerResource is available at: http://bioinformatics.charite.de/cancerresource/.

SuperSweet--a resource on natural and artificial sweetening agents

A vast number of sweet tasting molecules are known, encompassing small compounds, carbohydrates, d-amino acids and large proteins. Carbohydrates play a particularly big role in human diet. The replacement of sugars in food with artificial sweeteners is common and is a general approach to prevent cavities, obesity and associated diseases such as diabetes and hyperlipidemia. Knowledge about the molecular basis of taste may reveal new strategies to overcome diet-induced diseases. In this context, the design of safe, low-calorie sweeteners is particularly important. Here, we provide a comprehensive collection of carbohydrates, artificial sweeteners and other sweet tasting agents like proteins and peptides. Additionally, structural information and properties such as number of calories, therapeutic annotations and a sweetness-index are stored in SuperSweet. Currently, the database consists of more than 8000 sweet molecules. Moreover, the database provides a modeled 3D structure of the sweet taste receptor and binding poses of the small sweet molecules. These binding poses provide hints for the design of new sweeteners. A user-friendly graphical interface allows similarity searching, visualization of docked sweeteners into the receptor etc. A sweetener classification tree and browsing features allow quick requests to be made to the database. The database is freely available at: http://bioinformatics.charite.de/sweet/.

The metabolic enhancer piracetam ameliorates the impairment of mitochondrial function and neurite outgrowth induced by beta-amyloid peptide

BACKGROUND AND PURPOSE

beta-Amyloid peptide (Abeta) is implicated in the pathogenesis of Alzheimer's disease by initiating a cascade of events from mitochondrial dysfunction to neuronal death. The metabolic enhancer piracetam has been shown to improve mitochondrial dysfunction following brain aging and experimentally induced oxidative stress.

EXPERIMENTAL APPROACH

We used cell lines (PC12 and HEK cells) and murine dissociated brain cells. The protective effects of piracetam in vitro and ex vivo on Abeta-induced impairment of mitochondrial function (as mitochondrial membrane potential and ATP production), on secretion of soluble Abeta and on neurite outgrowth in PC12 cells were investigated.

KEY RESULTS

Piracetam improves mitochondrial function of PC12 cells and acutely dissociated brain cells from young NMRI mice following exposure to extracellular Abeta(1-42). Similar protective effects against Abeta(1-42) were observed in dissociated brain cells from aged NMRI mice, or mice transgenic for mutant human amyloid precursor protein (APP) treated with piracetam for 14 days. Soluble Abeta load was markedly diminished in the brain of those animals after treatment with piracetam. Abeta production by HEK cells stably transfected with mutant human APP was elevated by oxidative stress and this was reduced by piracetam. Impairment of neuritogenesis is an important consequence of Abeta-induced mitochondrial dysfunction and Abeta-induced reduction of neurite growth in PC12 cells was substantially improved by piracetam.

CONCLUSION AND IMPLICATIONS

Our findings strongly support the concept of improving mitochondrial function as an approach to ameliorate the detrimental effects of Abeta on brain function.

Survival, neuron-like differentiation and functionality of mesenchymal stem cells in neurotoxic environment: the critical role of erythropoietin

Mesenchymal stem cells (MSCs) can ameliorate symptoms in several neurodegenerative diseases. However, the toxic environment of a degenerating central nervous system (CNS) characterized by hypoxia, glutamate (Glu) excess and amyloid beta (Abeta) pathology may hamper the survival and regenerative/replacing capacities of engrafted stem cells. Indeed, human MSC (hMSC) exposed to hypoxia were disabled in (i) the capacity of their muscarinic receptors (mAChRs) to respond to acetylcholine (ACh) with a transient increase in intracellular [Ca(2+)], (ii) their capacity to metabolize Glu, reflected by a strong decrease in glutamine synthetase activity, and (iii) their survival on exposure to Glu. Cocultivation of MSC with PC12 cells expressing the amyloid precursor protein gene (APPsw-PC12) increased the release of IL-6 from MSC. HMSC exposed to erythropoietin (EPO) showed a cholinergic neuron-like phenotype reflected by increased cellular levels of choline acetyltransferase, ACh and mAChR. All their functional deficits observed under hypoxia, Glu exposure and APPsw-PC12 cocultivation were reversed by the application of EPO, which increased the expression of Wnt3a. EPO also enhanced the metabolism of Abeta in MSC by increasing their neprilysin content. Our data show that cholinergic neuron-like differentiation of MSC, their functionality and resistance to a neurotoxic environment is regulated and can be improved by EPO, highlighting its potential for optimizing cellular therapies of the CNS.

Enhanced apoptosis, oxidative stress and mitochondrial dysfunction in lymphocytes as potential biomarkers for Alzheimer's disease

Alzheimer's disease (AD) is the most common progressive neurodegenerative disease. Today, AD affects millions of people worldwide and the number of AD cases will increase with increased life expectancy. The AD brain is marked by severe neurodegeneration like the loss of synapses and neurons, atrophy and depletion of neurotransmitter systems in the hippocampus and cerebral cortex. Recent findings suggest that these pathological changes are causally induced by mitochondrial dysfunction, increased oxidative stress and elevated apoptosis. Until now, AD cannot be diagnosed by a valid clinical method or a biomarker before the disease has progressed so far that dementia is present. Furthermore, no valid method is available to determine which patient with mild cognitive impairment (MCI) will progress to AD. Therefore, a correct diagnosis in the early stage of AD is not only of importance considering that early drug treatment is more effective but also that the psychological burden of the patients and relatives could be decreased. In this review, we discuss the potential role of elevated apoptosis, increased oxidative stress and mitochondrial dysfunction as biomarker for AD in a peripheral cell model, the lymphocytes.

The PEA-15/PED protein protects glioblastoma cells from glucose deprivation-induced apoptosis via the ERK/MAP kinase pathway

PEA-15 (phosphoprotein enriched in astrocytes 15 kDa) is a death effector domain-containing protein, which is involved in the regulation of apoptotic cell death. Since PEA-15 is highly expressed in cells of glial origin, we studied the role of PEA-15 in human malignant brain tumors. Immunohistochemical analysis of PEA-15 expression shows strong immunoreactivity in astrocytomas and glioblastomas. Phosphorylation of PEA-15 at Ser(116) is found in vivo in perinecrotic areas in glioblastomas and in vitro after glucose deprivation of glioblastoma cells. Overexpression of PEA-15 induces a marked resistance against glucose deprivation-induced apoptosis, whereas small interfering RNA (siRNA)-mediated downregulation of endogenous PEA-15 results in the sensitization to glucose withdrawal-mediated cell death. This antiapoptotic activity of PEA-15 under low glucose conditions depends on its phosphorylation at Ser(116). Moreover, siRNA-mediated knockdown of PEA-15 abolishes the tumorigenicity of U87MG glioblastoma cells in vivo. PEA-15 regulates the level of phosphorylated extracellular-regulated kinase (ERK)1/2 in glioblastoma cells and the PEA-15-dependent protection from glucose deprivation-induced cell death requires ERK1/2 signaling. PEA-15 transcriptionally upregulates the Glucose Transporter 3, which is abrogated by the inhibition of ERK1/2 phosphorylation. Taken together, our findings suggest that Ser(116)-phosphorylated PEA-15 renders glioma cells resistant to glucose deprivation-mediated cell death as encountered in poor microenvironments, for example in perinecrotic areas of glioblastomas.

[The PEA-15 protein induces resistance against glucose deprivation-induced cell death via the ERK/MAP kinase pathway]

PEA-15 (Phosphoprotein enriched in astrocytes 15 kD) is a death effector domain-containing protein, which is involved in the regulation of apoptotic cell death. Since PEA-15 is highly expressed in cells of glial origin, we studied the role of PEA-15 in human malignant brain tumors. Immunohistochemical analysis of PEA-15 expression shows strong immunoreactivity in astrocytomas and glioblastomas. Phosphorylation of PEA-15 at Ser116 is found in vivo in perinecrotic areas in glioblastomas and in vitro after glucose deprivation of glioblastoma cells. Overexpression of PEA-15 induces a marked resistance against glucose deprivation-induced apoptosis, whereas siRNA-mediated down-regulation of endogenous PEA-15 results in the sensitization to glucose withdrawal-mediated cell death. This anti-apoptotic activity of PEA-15 under low glucose conditions depends on its phosphorylation at Ser116 Moreover, siRNA-mediated knockdown of PEA-15 abolishes the tumorigenicity of U87MG glioblastoma cells in vivo. PEA-15 regulates the level of phosphorylated ERK1/2 in glioblastoma cells and the PEA-15-dependent protection from glucose deprivation-induced cell death requires ERK1/2 signaling. PEA-15 transcriptionally up-regulates the glucose transporter 3, which is abrogated by the inhibition of ERK1/2 phosphorylation. Taken together, our findings suggest that Ser116-phosphorylated PEA-15 renders glioma cells resistant to glucose deprivation-mediated cell death as encountered in poor microenvironments, e.g. in perinecrotic areas of glioblastomas.

Apoptosis of CD4+ T and Natural Killer Cells in Alzheimer's Disease

BACKGROUND

Immunotherapy appears to be a potent treatment against Alzheimer's disease (AD), but the mechanisms underlying neural-immune interaction are still not known.

METHODS

Here, we determined cell death and distribution of lymphocyte subsets of peripheral blood mononuclear cells (PBMC) in AD and aging, e.g. T (CD4+ CD3+, CD8+ CD3+), B (CD19+) and NK (CD16++CD56+) cells.

RESULTS

Increased apoptosis was found in CD4+ T and NK cells in AD, while in aging all subsets were affected. The expression of anti-apoptotic Bcl2 correlated with observed cell death in T-helper and B cells irrespective of dementia. The levels of Bcl2 in T-cells were significantly increased in mild AD. Apoptosis and Bcl2 levels were also elevated in the APP (751SL)xPS1 (M146L) transgenic mouse model.

CONCLUSION

The mechanisms triggering apoptosis and activation of lymphocytes in AD appear therefore to be different than those in immunosenescence and possibly bear an important biomarker to monitor immunotherapy in AD.

Pineal and cortical melatonin receptors MT1 and MT2 are decreased in Alzheimer's disease

The pineal hormone melatonin is involved in physiological transduction of temporal information from the light dark cycle to circadian and seasonal behavioural rhythms, as well as possessing neuroprotective properties. Melatonin and its receptors MT1 and MT2, which belong to the family of G protein-coupled receptors, are impaired in Alzheimer's disease (AD) with severe consequences to neuropathology and clinical symptoms. The present data provides the first immunohistochemical evidence for the cellular localization of the both melatonin receptors in the human pineal gland and occipital cortex, and demonstrates their alterations in AD. We localized MT1 and MT2 in the pineal gland and occipital cortex of 7 elderly controls and 11 AD patients using immunohistochemistry with peroxidase-staining. In the pineal gland both MT1 and MT2 were localized to pinealocytes, whereas in the cortex both receptors were expressed in some pyramidal and non-pyramidal cells. In patients with AD, parallel to degenerative tissue changes, there was an overall decrease in the intensity of receptors in both brain regions. In line with our previous findings, melatonin receptor expression in AD is impaired in two additional brain areas, and may contribute to disease pathology.