Flavopiridol Pharmacogenetics: Clinical and Functional Evidence for the Role of SLCO1B1/OATP1B1 in Flavopiridol Disposition

Flavopiridol is a cyclin-dependent kinase inhibitor in phase II clinical development for treatment of various forms of cancer. When administered with a pharmacokinetically (PK)-directed dosing schedule, flavopiridol exhibited striking activity in patients with refractory chronic lymphocytic leukemia. This study aimed to evaluate pharmacogenetic factors associated with inter-individual variability in pharmacokinetics and outcomes associated with flavopiridol therapy.Thirty-five patients who received single-agent flavopiridol via the PK-directed schedule were genotyped for 189 polymorphisms in genes encoding 56 drug metabolizing enzymes and transporters. Genotypes were evaluated in univariate and multivariate analyses as covariates in a population PK model. Transport of flavopiridol and its glucuronide metabolite was evaluated in uptake assays in HEK-293 and MDCK-II cells transiently transfected with SLCO1B1. Polymorphisms in ABCC2, ABCG2, UGT1A1, UGT1A9, and SLCO1B1 were found to significantly correlate with flavopiridol PK in univariate analysis. Transport assay results indicated both flavopiridol and flavopiridol-glucuronide are substrates of the SLCO1B1/OATP1B1 transporter. Covariates incorporated into the final population PK model included bilirubin, SLCO1B1 rs11045819 and ABCC2 rs8187710. Associations were also observed between genotype and response. To validate these findings, a second set of data with 51 patients was evaluated, and overall trends for associations between PK and PGx were found to be consistent.Polymorphisms in transport genes were found to be associated with flavopiridol disposition and outcomes. Observed clinical associations with SLCO1B1 were functionally validated indicating for the first time its relevance as a transporter of flavopiridol and its glucuronide metabolite. A second 51-patient dataset indicated similar trends between genotype in the SLCO1B1 and other candidate genes, thus providing support for these findings. Further study in larger patient populations will be necessary to fully characterize and validate the clinical impact of polymorphisms in SLCO1B1 and other transporter and metabolizing enzyme genes on outcomes from flavopiridol therapy

Infectious Speciation Revisited: Impact of Symbiont-Depletion on Female Fitness and Mating Behavior of Drosophila paulistorum

The neotropical Drosophila paulistorum superspecies, consisting of at least six geographically overlapping but reproductively isolated semispecies, has been the object of extensive research since at least 1955, when it was initially trapped mid-evolution in flagrant statu nascendi. In this classic system females express strong premating isolation patterns against mates belonging to any other semispecies, and yet uncharacterized microbial reproductive tract symbionts were described triggering hybrid inviability and male sterility. Based on theoretical models and limited experimental data, prime candidates fostering symbiont-driven speciation in arthropods are intracellular bacteria belonging to the genus Wolbachia. They are maternally inherited symbionts of many arthropods capable of manipulating host reproductive biology for their own benefits. However, it is an ongoing debate as to whether or not reproductive symbionts are capable of driving host speciation in nature and if so, to what extent. Here we have reevaluated this classic case of infectious speciation by means of present day molecular approaches and artificial symbiont depletion experiments. We have isolated the α-proteobacteria Wolbachia as the maternally transmitted core endosymbionts of all D. paulistorum semispecies that have coevolved towards obligate mutualism with their respective native hosts. In hybrids, however, these mutualists transform into pathogens by overreplication causing embryonic inviability and male sterility. We show that experimental reduction in native Wolbachia titer causes alterations in sex ratio, fecundity, and mate discrimination. Our results indicate that formerly designated Mycoplasma-like organisms are most likely Wolbachia that have evolved by becoming essential mutualistic symbionts in their respective natural hosts; they have the potential to trigger pre- and postmating isolation. Furthermore, in light of our new findings, we revisit the concept of infectious speciation and discuss potential mechanisms that can restrict or promote symbiont-induced speciation at post- and prezygotic levels in nature and under artificial laboratory conditions

Clinical and preclinical studies of cognitive sequelae in childhood leukemia survivors

List of figures List of tables Abbreviations Scientific summary Populariserende samenvatting Wetenschappelijke samenvatting 1. Introduction 1.1 Childhood haematological malignancies 1.2 Chemotherapy-induced cognitive sequelae 1.3 Chemotherapy in childhood leukemia 1.3.1 Chemotherapeutics: medical gains, medical costs 1.3.2 Methotrexate: high gains, high costs 1.3.2.1 Folate cycle 1.3.2.2 Effects of methotrexate 1.3.2.3 MTHFR enzyme 1.4 Tau and phosphorylated Tau as markers for neurotoxicity 1.5 Neuro-inflammation: from benefit or burden 1.6 Aims and hypotheses 2. Experimental rationale, subjects and methodology 2.1 Rodent studies 2.1.1 Animals 2.1.2 Drugs 2.1.3 Collection of tissue 2.1.3.1 Histology 2.1.3.2 Analysis of serum and CSF metabolites 2.1.4 Unpredictable chronic mild stress 2.1.5 Neurobehavioral testing 2.2 Human study 2.2.1 Participants 2.2.2 Neurocognitive testing 2.2.2.1 Intelligence testing 2.2.2.2 Memory 2.2.2.3 Executive functioning 2.2.3 MTHFR genotyping 3. Acute methotrexate suppresses CSF folate, increases levels of Tau and induces long-lasting cognitive deficits in young mice 3.1 Abstract 3.2 Introduction 3.3 Materials and methods 3.4 Results 3.5 Discussion 4. Immunomodulating effects of glucocorticosteroids attenuate neurotoxicity in mice 4.1 Abstract 4.2 Introduction 4.3 Materials and methods 4.4 Results 4.5 Discussion 5. Early life stress aggravates chemotherapy-induced cognitive deficits in mice 5.1 Abstract 5.2 Introduction 5.3 Materials and methods 5.4 Results 5.5 Discussion 6. Neurocognitive sequelae in adult childhood-leukemia survivors related to levels of phosphorylated Tau 7. Altered brain connectivity and impaired cognitive flexibility in non-irradiated adult survivors of childhood leukemia 7.1 Abstract 7.2 Introduction 7.3 Materials and methods 7.4 Results 7.5 Discussion 8. Adult childhood-leukemia survivors with MTHFR1298CC genotype more at risk for alterations in cortical connectivity and neurocognitive sequelae of chemotherapy 8.1 Abstract 8.2 Introduction 8.3 Materials and methods 8.4 Results 8.5 Discussion 9. General discussion and future perspectives 10. Bibliography 11. Curriculum vitae 12. Dankwoord – het vliegend tuignrpages: 180status: publishe

G37R SOD1 mutant alters mitochondrial complex I activity, Ca(2+) uptake and ATP production.

Item does not contain fulltextAmyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by selective death of motor neurons. Mutations in Cu/Zn superoxide dismutase-1 (SOD1) cause familial ALS but the molecular mechanisms whereby these mutations induce motor neuron death remain controversial. Here, we show that stable overexpression of mutant human SOD1 (G37R) - but not wild-type SOD1 (wt-SOD1) - in mouse neuroblastoma cells (N2a) results in morphological abnormalities of mitochondria accompanied by several dysfunctions. Activity of the oxidative phosphorylation complex I was significantly reduced in G37R cells and correlated with lower mitochondrial membrane potential and reduced levels of cytosolic ATP. Using targeted chimeric aequorin we further analyzed the consequences of mitochondrial dysfunction on cellular Ca(2+) handling. Mitochondrial Ca(2+) uptake, elicited by IP(3)-induced Ca(2+) release from endoplasmic reticulum (ER) was significantly reduced in G37R cells, while uptake induced by a brief Ca(2+) pulse was not affected in permeabilized cells. The decreased mitochondrial Ca(2+) uptake resulted in increased cytosolic Ca(2+) transients, whereas ER Ca(2+) load and resting cytosolic Ca(2+) levels were not affected. Together, these findings suggest that the mechanism linking mutant G37R SOD1 and ALS involves mitochondrial respiratory chain deficiency resulting in ATP loss and impairment of mitochondrial and cytosolic Ca(2+) homeostasis.1 april 201

Definition of the Microecological Status and Diagnosis of the Human's Infections, using the Method of Chromatography-Mass Spectrometry

Показана возможность использования метода хромато-масс-спектрометрии для оценки микроэкологического статуса организма человека по масс-спектрометрии микробных маркеров, в качестве которых выступают жирные кислоты, стерины, альдегиды. По анализу жирных кислот методом ХМС можно количественно определять наличие 57 микроорганизмов в ротовой полости человека.It was shown the possibility of using the method of chromatography-mass spectrometry to estimate microecological status of the human by the method of mass spectrometry microbial markers, which are mainly fatty acids, sterols, aldehydes. For analysis of fatty acids by CMS it is possible quantify the presence of 57 microorganisms in the human oral cavity