Uncoupling of Cytochrome P450 2B6 and stimulation of reactive oxygen species production in pharmacogenomic alleles affected by interethnic variability.

Cytochrome P450 mediated substrate metabolism is generally characterized by the formation of reactive intermediates. In vitro and in vivo reaction uncoupling, results in the accumulation and dissociation of reactive intermediates, leading to increased ROS formation. The susceptibility towards uncoupling and altered metabolic activity is partly modulated by pharmacogenomic alleles resulting in amino acid substitutions. A large variability in the prevalence of these alleles has been demonstrated in CYP2B6, with some being predominantly unique to African populations. The aim of this study is to characterize the uncoupling potential of recombinant CYP2B6*1, CYP2B6*6 and CYP2B6*34 metabolism of specific substrates. Therefore, functional effects of these alterations on enzyme activity were determined by quantification of bupropion, efavirenz and ketamine biotransformation using HPLC-MS/MS. Determination of H2O2 levels was performed by the AmplexRed/horseradish peroxidase assay. Our studies of the amino acid substitutions Q172H, K262R and R487S revealed an exclusive use of the peroxide shunt for the metabolism of bupropion and ketamine by CYP2B6*K262R. Ketamine was also identified as a trigger for the peroxide shunt in CYP2B6*1 and all variants. Concurrently, ketamine acted as an uncoupler for all enzymes. We further showed that the expressed CYP2B6*34 allele results in the highest H2O2 formation. We therefore conclude that the reaction uncoupling and peroxide shunt are directly linked and can be substrate specifically induced with K262R carriers being most likely to use the peroxide shunt and R487S carrier being most prone to reaction uncoupling. This elucidates the functional diversity of pharmacogenomics in drug metabolism and safety.

Sex- and region-specific cortical and hippocampal whole genome transcriptome profiles from control and APP/PS1 Alzheimer's disease mice.

A variety of Alzheimer's disease (AD) mouse models has been established and characterized within the last decades. To get an integrative view of the sophisticated etiopathogenesis of AD, whole genome transcriptome studies turned out to be indispensable. Here we carried out microarray data collection based on RNA extracted from the retrosplenial cortex and hippocampus of age-matched, eight months old male and female APP/PS1 AD mice and control animals to perform sex- and brain region specific analysis of transcriptome profiles. The results of our studies reveal novel, detailed insight into differentially expressed signature genes and related fold changes in the individual APP/PS1 subgroups. Gene ontology and Venn analysis unmasked that intersectional, upregulated genes were predominantly involved in, e.g., activation of microglial, astrocytic and neutrophilic cells, innate immune response/immune effector response, neuroinflammation, phagosome/proteasome activation, and synaptic transmission. The number of (intersectional) downregulated genes was substantially less in the different subgroups and related GO categories included, e.g., the synaptic vesicle docking/fusion machinery, synaptic transmission, rRNA processing, ubiquitination, proteasome degradation, histone modification and cellular senescence. Importantly, this is the first study to systematically unravel sex- and brain region-specific transcriptome fingerprints/signature genes in APP/PS1 mice. The latter will be of central relevance in future preclinical and clinical AD related studies, biomarker characterization and personalized medicinal approaches.

Current status of the analytical validation of next generation sequencing applications for pharmacogenetic profiling.

BACKGROUND: Analytical validity is a prerequisite to use a next generation sequencing (NGS)-based application as an in vitro diagnostic test or a companion diagnostic in clinical practice. Currently, in the United States and the European Union, the intended use of such NGS-based tests does not refer to guided drug therapy on the basis of pharmacogenetic profiling of drug metabolizing enzymes, although the value of pharmacogenetic testing has been reported. However, in research, a large variety of NGS-based tests are used and have been confirmed to be at least comparable to array-based testing. METHODS AND RESULTS: A systematic evaluation was performed screening and assessing published literature on analytical validation of NGS applications for pharmacogenetic profiling of CYP2C9, CYP2C19, CYP2D6, VKORC1 and/or UGT1A1. Although NGS applications are also increasingly used for implementation assessments in clinical practice, we show in the present systematic literature evaluation that published information on the current status of analytical validation of NGS applications targeting drug metabolizing enzymes is scarce. Furthermore, a comprehensive performance evaluation of whole exome and whole genome sequencing with the intended use for pharmacogenetic profiling has not been published so far. CONCLUSIONS: A standard in reporting on analytical validation of NGS-based tests is not in place yet. Therefore, many relevant performance criteria are not addressed in published literature. For an appropriate analytical validation of an NGS-based qualitative test for pharmacogenetic profiling at least accuracy, precision, limit of detection and specificity should be addressed to facilitate the implementation of such tests in clinical use.

Whole genome transcriptome data from the WT cortex and hippocampus of female and male control and APP/PS1 Alzheimer's disease mice.

A variety of Alzheimer disease (AD) mouse models has been established and characterized within the last decades. These models are generated to meet the principal criteria of AD isomorphism, homology and predictability to a maximum extent. To get an integrative view of the sophisticated etiopathogenesis of AD, whole genome transcriptome data analysis turns out to be indispensable. Here, we present a microarray-based transcriptome data collection based on RNA extracted from the retrosplenial (RS) cortex and the hippocampus of APP/PS1 AD mice and control animals. Experimental animals were age matched and importantly, both sexes were considered separately. Isolated RNA was purified, quantified und quality controlled prior to the hybridization procedure with SurePrint G3 Mouse Gene Expression v2 8 × 60K microarrays. Following immunofluorescent measurement und preprocessing/extraction of image data, raw transcriptome data were uploaded including differentially expressed gene candidates and related fold changes in APP/PS1 AD mice and controls. Our data allow further insight into alterations in gene transcript levels in APP/PS1 AD mice compared to controls and enable the reader/user to carry out complex transcriptome analysis to characterize potential age-, sex- and brain-region-specific alterations in e.g., neuroinflammatory, immunological, neurodegenerative and ion channel pathways.

Use of overactive bladder anticholinergic medications associated with falls leading to emergency department visits: results from the ADRED study.

PURPOSE: Drug intake might be a modifiable factor for the individual fall-risk of older adults, and anticholinergic properties of drugs need to be considered. This study is aimed at analyzing the association of older adults' individual anticholinergic load with particular focus on use of overactive bladder anticholinergic medications with falls in multi-medicated patients. MATERIALS AND METHODS: Cases of the prospective, observational, multi-center study on adverse drug reactions leading to emergency departments (ADRED study) between 2015 and 2018 in Germany were analyzed comparing the exposure of overactive bladder anticholinergic medications on the chance to present with a fall with patients without exposure. Logistic regression analysis was used adjusting for pre-existing conditions, drug exposure, and the individual anticholinergic burden by drug use. To this end, a combination of seven expert-based anticholinergic rating scales was used. RESULTS: The anticholinergic burden was higher in patients with overactive bladder anticholinergic medications (median 2 [1; 3]) compared to not taking drugs of interest. Presenting with a fall was associated with overactive bladder anticholinergic medications (odds ratio (OR) 2.34 [95% confidence interval 1.14-4.82]). The use of fall-risk increasing drugs was likewise associated (OR 2.30 [1.32-4.00]). The anticholinergic burden itself seemed not to be associated with falls (OR 1.01 [0.90-1.12]). CONCLUSIONS: Although falls occur multifactorial in older adults and confounding by indication cannot be ruled out, the indication for a drug treatment should be decided with caution when other, non-pharmacological treatment options have been tried. GERMAN CLINICAL TRIAL REGISTER: DRKS-ID: DRKS00008979, registration date 01/11/2017.

Inhalation therapies in COPD - adverse drug reactions impact on emergency department presentations.

PURPOSE: Inhaled drugs have been cornerstones in the treatment of chronic obstructive pulmonary disease (COPD) for decades and show a high prescription volume. Due to the local application, drug safety issues of these therapies are often underestimated by professionals and patients. Data about adverse drug reactions (ADRs) caused by inhaled therapy in patients with COPD and polypharmacy are rare. We aimed to analyze the use and relevance of inhaled therapies in those patients in relation to ADR complaints, which were severe enough to warrant presentation to the emergency department. METHODS: Emergency department cases due to suspected ADRs of the ADRED database (n = 2939, "Adverse Drug Reactions in Emergency Departments"; DRKS-ID: DRKS00008979, registration date 01/11/2017) were analyzed for inhaled drugs in patients with COPD. ADRs in cases with overdosed inhaled drugs were compared to non-overdosed cases. ADRs, potentially caused by inhaled drugs, were evaluated, clustered into complexes, and assessed for association with inhaled drug classes. RESULTS: Of the 269 included COPD cases, 67% (n = 180) received inhaled therapy. In 16% (n = 28), these therapies were overdosed. Overdosed cases presented the complexes of malaise and local symptoms more frequently. Related to the use of inhaled anticholinergics, local (dysphagia-like) and related to inhaled beta-2 agonists, local (dysphagia-like) and sympathomimetic-like ADRs presented more frequently. CONCLUSION: Overdosed inhaled therapies in patients with COPD lead to relevant ADRs and impact on emergency room presentations. These are rarely associated to inhaled therapy by healthcare professionals or patients. Due to the high volume of inhaled drug prescriptions, pharmacovigilance and patient education should be more focused in patients with COPD. German Clinical Trial Register: DRKS-ID: DRKS00008979.

Green Tea Extract to Prevent Colorectal Adenomas, Results of a Randomized, Placebo-Controlled Clinical Trial.

INTRODUCTION: Preclinical, epidemiological, and small clinical studies suggest that green tea extract (GTE) and its major active component epigallocatechingallate (EGCG) exhibit antineoplastic effects in the colorectum. METHODS: A randomized, double-blind trial of GTE standardized to 150 mg of EGCG b.i.d. vs placebo over 3 years was conducted to prevent colorectal adenomas (n = 1,001 with colon adenomas enrolled, 40 German centers). Randomization (1:1, n = 879) was performed after a 4-week run-in with GTE for safety assessment. The primary end point was the presence of adenoma/colorectal cancer at the follow-up colonoscopy 3 years after randomization. RESULTS: The safety profile of GTE was favorable with no major differences in adverse events between the 2 well-balanced groups. Adenoma rate in the modified intention-to-treat set (all randomized participants [intention-to-treat population] and a follow-up colonoscopy 26-44 months after randomization; n = 632) was 55.7% in the placebo and 51.1% in the GTE groups. This 4.6% difference was not statistically significant (adjusted relative risk 0.905; P = 0.1613). The respective figures for the per-protocol population were 54.3% (151/278) in the placebo group and 48.3% (129/267) in the GTE group, indicating a slightly lower adenoma rate in the GTE group, which was not significant (adjusted relative risk 0.883; P = 0.1169). DISCUSSION: GTE was well tolerated, but there was no statistically significant difference in the adenoma rate between the GTE and the placebo groups in the whole study population.

Evaluation of the EMPAR study population on the basis of metabolic phenotypes of selected pharmacogenes.

The impact of genetic variability of pharmacogenes as a possible risk factor for adverse drug reactions is elucidated in the EMPAR (Einfluss metabolischer Profile auf die Arzneimitteltherapiesicherheit in der Routineversorgung/English: influence of metabolic profiles on the safety of drug therapy in routine care) study. EMPAR evaluates possible associations of pharmacogenetically predicted metabolic profiles relevant for the metabolism of frequently prescribed cardiovascular drugs. Based on a German study population of 10,748 participants providing access to healthcare claims data and DNA samples for pharmacogenetic assessment, first analyses were performed and evaluated. The aim of this first evaluation was the characterization of the study population with regard to general parameters such as age, gender, comorbidity, and polypharmacy at baseline (baseline year) as well as important combinations of cardiovascular drugs with relevant genetic variants and predicted metabolic phenotypes. The study was registered in the German Clinical Trials Register (DRKS) on July 6, 2018 (DRKS00013909).

Population genetic polymorphisms of pharmacogenes in Zimbabwe, a potential guide for the safe and efficacious use of medicines in people of African ancestry.

OBJECTIVE: Pharmacogenomics (PGx) is a clinically significant factor in the safe and efficacious use of medicines. While PGx knowledge is abundant for other populations, there are scarce PGx data on African populations and is little knowledge on drug-gene interactions for medicines used to treat diseases common in Africa. The aim of this study was to use a custom-designed open array to genotype clinically actionable variants in a Zimbabwean population. This study also identified some of the commonly used drugs in Zimbabwe and the associated genes involved in their metabolism. METHODS: A custom-designed open array that covers 120 genetic variants was used to genotype 522 black Zimbabwean healthy volunteers using TaqMan-based single nucleotide polymorphism genotyping. Data were also accessed from Essential Drugs' List in Zimbabwe (EDLIZ), and the medicines were grouped into the associated biomarker groups based on their metabolism. We also estimated the national drug procurement levels for medicines that could benefit from PGx-guided use based on the data obtained from the national authorities in Zimbabwe. RESULTS: The results demonstrate the applicability of an open-array chip in simultaneously determining multiple genetic variants in an individual, thus significantly reducing cost and time to generate PGx data. There were significantly high frequencies of African-specific variants, such as the CYP2D6*17 and *29 variants and the CYP2B6*18 variant. The data obtained showed that the Zimbabwean population exhibits PGx variations in genes important for the safe and efficacious use of drugs approved by the EDLIZ and are procured at significantly large amounts annually. The study has established a cohort of genotyped healthy volunteers that can be accessed and used in the conduct of clinical pharmacogenetic studies for drugs entering a market of people of predominantly African ancestry. CONCLUSION: Our study demonstrated the potential benefit of integrating PGx in Zimbabwe for the safe and efficacious use of drugs that are commonly used.

Molecular Genetic Techniques in Biomarker Analysis Relevant for Drugs Centrally Approved in Europe.

On the basis of scientific evidence, information on the option, recommendation or requirement to test for pharmacogenetic or pharmacogenomic biomarkers is incorporated in the Summary of Product Characteristics of an increasing number of drugs in Europe. A screening of the Genetic Testing Registry (GTR) showed that a variety of molecular genetic testing methods is currently offered worldwide in testing services with regard to according drugs and biomarkers. Thereby, among the methodology indicated in the screened GTR category 'Molecular Genetics', next-generation sequencing is applied for identification of the largest proportion of evaluated biomarkers that are relevant for therapeutic management of centrally approved drugs in Europe. However, sufficient information on regulatory clearances, clinical utility, analytical and clinical validity of applied methods is rarely provided.

Catch Me if You Can: the Crosstalk of Zika Virus and the Restriction Factor Tetherin.

Zika virus (ZIKV) is a flavivirus that is mainly transmitted by Aedes mosquitos and normally causes mild symptoms. During the outbreak in the Americas in 2015, it was associated with more severe implications, like microcephaly in newborns and the Guillain-Barré syndrome. The lack of specific vaccines and cures strengthens the need for a deeper understanding of the virus life cycle and virus-host interactions. The restriction factor tetherin (THN) is an interferon-inducible cellular protein with broad antiviral properties. It is known to inhibit the release of various enveloped viruses by tethering them to each other and the cell membrane, thereby preventing their further spread. On the other hand, different viruses have developed various escape strategies against THN. Analysis of the cross-talk between ZIKV and THN revealed that, despite a strong induction of THN mRNA expression in ZIKV-infected cells, this is not reflected by an elevated protein level of THN. Contrariwise, the THN protein level is decreased due to a reduced half-life. The increased degradation of THN in ZIKV infected cells involves the endo-lysosomal system but does not depend on the early steps of autophagy. Enrichment of THN by depletion of the ESCRT-0 protein HRS diminishes ZIKV release and spread, which points out the capacity of THN to restrict ZIKV and explains the enhanced THN degradation in infected cells as an effective viral escape strategy. IMPORTANCE Although tetherin expression is strongly induced by ZIKV infection there is a reduction in the amount of tetherin protein. This is due to enhanced lysosomal degradation. However, if the tetherin level is rescued then the release of ZIKV is impaired. This shows that tetherin is a restriction factor for ZIKV, and the induction of an efficient degradation represents a viral escape strategy. To our knowledge, this is the first study that describes and characterizes tetherin as a restriction factor for the ZIKV life cycle.

Individualized versus Standardized Risk Assessment in Patients at High Risk for Adverse Drug Reactions (The IDrug Randomized Controlled Trial)-Never Change a Running System?

The aim of this study was to compare effects of an individualized with a standardized risk assessment for adverse drug reactions to improve drug treatment with antithrombotic drugs in older adults. A randomized controlled trial was conducted in general practitioner (GP) offices. Patients aged 60 years and older, multi-morbid, taking antithrombotic drugs and at least one additional drug continuously were randomized to individualized and standardized risk assessment groups. Patients were followed up for nine months. A composite endpoint defined as at least one bleeding, thromboembolic event or death reported via a trigger list was used. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. In total, N = 340 patients were enrolled from 43 GP offices. Patients in the individualized risk assessment group met the composite endpoint more often than in the standardized group (OR 1.63 [95%CI 1.02-2.63]) with multiple adjustments. The OR was higher in patients on phenprocoumon treatment (OR 1.99 [95%CI 1.05-3.76]), and not significant on DOAC treatment (OR 1.52 [95%CI 0.63-3.69]). Pharmacogenenetic variants of CYP2C9, 2C19 and VKORC1 were not observed to be associated with the composite endpoint. The results of this study may indicate that the time point for implementing individualized risk assessments is of importance.

Genetic polymorphism of CYP2C19 and subcortical variability in the human adult brain.

Pharmacogenetic studies have shown involvement of cytochrome P450 enzymes in the metabolism of psychotropic drugs. However, expression and activity on endogenous substrates in the brain may underlie a constitutive role of these enzymes beyond drug metabolism. CYP2C19, which is expressed in the human fetal brain during neurodevelopment, shows affinity for endogenous compounds including monoaminergic neurotransmitters, steroid hormones, and endocannabinoids. In this study (N = 608), we looked at the genetic polymorphism of CYP2C19 and its potential associations with structural phenotypes of subcortical brain volume with structural imaging. Using two independent volume estimation techniques, we found converging evidence for a positive association between CYP2C19 activity scores, as inferred from the genotype, and basal ganglia and hippocampal volume. This association was present only in female individuals, raising the possibility that effects on brain morphology may arise through a mechanism involving the metabolism of estrogen steroids.

Cytogenetic and Biochemical Genetic Techniques for Personalized Drug Therapy in Europe.

For many authorized drugs, accumulating scientific evidence supports testing for predictive biomarkers to apply personalized therapy and support preventive measures regarding adverse drug reactions and treatment failure. Here, we review cytogenetic and biochemical genetic testing methods that are available to guide therapy with drugs centrally approved in the European Union (EU). We identified several methods and combinations of techniques registered in the Genetic Testing Registry (GTR), which can be used to guide therapy with drugs for which pharmacogenomic-related information is provided in the European public assessment reports. Although this registry provides information on genetic tests offered worldwide, we identified limitations regarding standard techniques applied in clinical practice and the information on test validity rarely provided in the according sections.

CYP2D6 in the Brain: Potential Impact on Adverse Drug Reactions in the Central Nervous System-Results From the ADRED Study.

Cytochrome P450 (CYP) 2D6 is a polymorphic enzyme expressed in the central nervous system (CNS), important in drug metabolism and with a potentially constitutive role in CNS function such as vigilance. This study aimed to analyze variability in CYP2D6 activity linked to vigilance-related adverse drug reactions (ADRs) in the CNS. A dataset of N = 2939 ADR cases of the prospective multicenter observational trial in emergency departments (EDs) (ADRED; trial registration: DRKS-ID: DRKS00008979) was analyzed. Dizziness as the most frequent reported CNS ADR symptom (12.7% of patients, n = 372) related to vigilance was chosen as the outcome. The association of dizziness with CYP2D6 activity markers was analyzed. The number of CYP2D6 substrates taken, a CYP2D6 saturation score (no, moderate, and strong saturation), a CYP2D6 saturation/inhibition score (no, weak, moderate, and strong), and composed CYP2D6 activity using a genotyped subsample (n = 740) calculating additive effects of genotype and CYP2D6 saturation by drug exposure were used as CYP2D6 activity markers. Effects were compared to other frequent nonvigilance-related CNS ADR symptoms (syncope and headache). Secondary analyses were conducted to control for other ADR symptoms frequently associated with dizziness (syncope, nausea, and falls). The majority of all patients (64.5%, n = 1895) took at least one drug metabolized by CYP2D6. Around a third took a CNS drug (32.5%, n = 955). The chance to present with drug-related dizziness to the ED increased with each CYP2D6 substrate taken by OR 1.11 [1.01-1.23]. Presenting with drug-related dizziness was more likely with CYP2D6 saturation and saturation/inhibition (both OR 1.27 [1.00-1.60]). The composed CYP2D6 activity was positively associated with dizziness (p = 0.028), while poorer activity affected patients more often with dizziness as an ADR. In contrast, nonvigilance-related ADR symptoms such as syncope and nausea were not consistently significantly associated with CYP2D6 activity markers. This study shows an association between the number of CYP2D6 substrates, the predicted CYP2D6 activity, and the occurrence of dizziness as a CNS ADR symptom. As dizziness is a vigilance-related CNS symptom, patients with low CYP2D6 activity might be more vulnerable to drug-related dizziness. This study underlines the need for understanding individual drug metabolism activity and individual risks for ADRs.

Association between miRNA signatures in serum samples from epidermal growth factor inhibitor treated patients and skin toxicity.

OBJECTIVE: Epidermal growth factor receptor inhibitors (EGFRI) are used as targeted cancer therapy. On average 70% of patients treated with EGFRIs suffer from skin toxicity. Studies showed a correlation between overall survival and the appearance of a skin rash, which is used as a biomarker for therapy efficacy. Micro RNAs (miRNA) as tumor or resistance biomarkers for cancer therapy are also highly investigated. In our study, we searched for associations of miRNA expression profiles in serum, with the severity of skin rash, in order to identify tentative therapy predictive biomarkers. MATERIALS AND METHODS: Five candidate miRNAs were selected, based on an earlier in vitro next-generation-sequencing-experiment and after literature search. MiR-21, miR-31, miR-17, miR-106b and miR-520e were investigated in serum samples from patients (n = 254) treated with EGFRI. The quantitative expression of miRNA was tested for association with the occurrence/severity of the rash. RESULTS: In our cohort of patients treated with EGFR inhibiting monoclonal antibodies, miR-21 and miR-520e serum concentrations were negatively correlated with severity of skin rash (p-value 0.000582 and 1.53e-07 linear-trend-test) whereas for miR-31, a positive correlation was observed (p-value 9.01e-06 linear-trend-test). CONCLUSIONS: This suggests that miR-21, miR-31 and miR-520e expression might be a treatment dependent marker for EGFRI induced skin rash.

Targeting Cholesterol Metabolism as Efficient Antiviral Strategy Against the Hepatitis E Virus.

BACKGROUND AND AIMS: The Hepatitis E virus hijacks the endosomal system for its release. These structures are highly dependent on cholesterol. Hence, this study investigates the impact of HEV on cholesterol-metabolism, the effect of intracellular cholesterol content on HEV-release and the potential of cholesterol-modulators to serve as antivirals. METHODS: Intracellular cholesterol-content of cells was modulated and impacts on HEV were monitored using qPCR, Western blot, microscopy, virus-titration and density-gradient centrifugation. Blood-lipids and HEV-RNA were routinely quantified in chronically infected patients during follow-up visits. RESULTS: In HEV-infected cells, decreased levels of cholesterol are found. In patients, HEV infection decreases serum-lipid concentrations. Importantly, statin treatment herein increases viral titers. Similarly, reduction of intracellular cholesterol via simvastatin treatment increases viral release in vitro. On the contrary, elevating intracellular cholesterol via LDL or 25-hydroxycholesterol strongly reduces viral release due to enhanced lysosomal degradation of HEV. Drug-induced elevation of intracellular cholesterol via fenofibrate or PSC833 impairs HEV release via the same mechanism. CONCLUSIONS: This study analyses the crosstalk between HEV and intracellular cholesterol. The results highlight the importance of an intact cholesterol homeostasis for HEV-release and thereby identify a potential target for antiviral strategies. Especially fenofibrate is considered a promising novel antiviral against HEV. Beyond this, the study may help clinicians evaluating co-treatments of HEV-infected patients with statins, as this may be counter indicated.

Effects of genetic variability of CYP2D6 on neural substrates of sustained attention during on-task activity.

The polymorphic drug-metabolizing enzyme CYP2D6, which is responsible for the metabolism of most psychoactive compounds, is expressed not only in the liver, but also in the brain. The effects of its marked genetic polymorphism on the individual capacity to metabolize drugs are well known, but its role in metabolism of neural substrates affecting behavior personality or cognition, suggested by its CNS expression, is a long-standing unresolved issue. To verify earlier findings suggesting a potential effect on attentional processes, we collected functional imaging data, while N = 415 participants performed a simple task in which the reward for correct responses varied. CYP2D6 allelic variants predicting higher levels of enzymatic activity level were positively associated with cortical activity in occipito-parietal areas as well as in a right lateralized network known to be activated by spatial attentional tasks. Reward-related modulation of activity in cortical areas was more pronounced in poor metabolizers. In conjunction with effects on reaction times, our findings provide evidence for reduced cognitive efficiency in rapid metabolizers compared to poor metabolizers in on-task attentional processes manifested through differential recruitment of a specific neural substrate.

Impact of Zika Virus Infection on Human Neural Stem Cell MicroRNA Signatures.

Zika virus (ZIKV) is a mosquito-borne virus, which can cause brain abnormalities in newborns, including microcephaly. MicroRNAs (miRNAs) are small non-coding RNAs, which post- transcriptionally regulate gene expression. They are involved in various processes including neurological development and host responses to viral infection, but their potential role in ZIKV pathogenesis remains poorly understood. MiRNAs can be incorporated into extracellular vesicles (EVs) and mediate cell-to-cell communication. While it is well known that in viral infections EVs carrying miRNAs can play a crucial role in disease pathogenesis, ZIKV effects on EV-delivered miRNAs and their contribution to ZIKV pathogenesis have not been elucidated. In the present study, we profiled intracellular and EV-derived miRNAs by next generation sequencing and analyzed the host mRNA transcriptome of neural stem cells during infection with ZIKV Uganda and French Polynesia strains. We identified numerous miRNAs, including miR-4792, which were dysregulated at the intracellular level and had altered levels in EVs during ZIKV infection. Integrated analyses of differentially expressed genes and miRNAs showed that ZIKV infection had an impact on processes associated with neurodevelopment and oxidative stress. Our results provide insights into the roles of intracellular and EV-associated host miRNAs in ZIKV pathogenesis.

Citalopram-induced pathways regulation and tentative treatment-outcome-predicting biomarkers in lymphoblastoid cell lines from depression patients.

Antidepressant therapy is still associated with delays in symptomatic improvement and low response rates. Incomplete understanding of molecular mechanisms underlying antidepressant effects hampered the identification of objective biomarkers for antidepressant response. In this work, we studied transcriptome-wide expression followed by pathway analysis in lymphoblastoid cell lines (LCLs) derived from 17 patients documented for response to SSRI antidepressants from the Munich Antidepressant Response Signatures (MARS) study upon short-term incubation (24 and 48 h) with citalopram. Candidate transcripts were further validated with qPCR in MARS LCLs from responders (n = 33) vs. non-responders (n = 36) and afterward in an independent cohort of treatment-resistant patients (n = 20) vs. first-line responders (n = 24) from the STAR*D study. In MARS cohort we observed significant associations of GAD1 (glutamate decarboxylase 1; p = 0.045), TBC1D9 (TBC1 Domain Family Member 9; p = 0.014-0.021) and NFIB (nuclear factor I B; p = 0.015-0.025) expression with response status, remission status and improvement in depression scale, respectively. Pathway analysis of citalopram-altered gene expression indicated response-status-dependent transcriptional reactions. Whereas in clinical responders neural function pathways were primarily up- or downregulated after incubation with citalopram, deregulated pathways in non-responders LCLs mainly involved cell adhesion and immune response. Results from the STAR*D study showed a marginal association of treatment-resistant depression with NFIB (p = 0.068) but not with GAD1 (p = 0.23) and TBC1D9 (p = 0.27). Our results propose the existence of distinct pathway regulation mechanisms in responders vs. non-responders and suggest GAD1, TBC1D9, and NFIB as tentative predictors for clinical response, full remission, and improvement in depression scale, respectively, with only a weak overlap in predictors of different therapy outcome phenotypes.