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Sphingosine-1-phosphate (S1P) is a potent lipid mediator released from activated platelets by an adenosine triphosphate (ATP)-dependent export mechanism. A candidate transport protein is the multidrug resistance protein 4 (MRP4/ABCC4), an ATP-dependent transporter highly expressed in platelets. Furthermore, several statins are known to affect platelet functions and exhibit antithrombotic properties. This study determines the involvement of MRP4 in the transport of S1P and a possible interference by statins. Transport studies in membrane vesicles of Sf9 cells containing recombinant human MRP4 revealed that MRP4 mediates ATP-dependent transport of fluorescein- and tritium-labelled S1P. Also, ATP-dependent S1P transport in platelet membrane vesicles containing endogenous MRP4 was inhibited by the MRP inhibitor MK571 and the MRP4-selective compound Ceefourin-1. Confocal microscopy using fluorescein-labelled S1P as well as boron-dipyrromethene (BODIPY)-labelled sphingosine indicated association of S1P and MRP4 in human platelets. In MRP4-deficient mice, agonist-induced S1P secretion was reduced compared with matched wild-type C57Bl/6 mice and platelet S1P concentrations were lower. Fluvastatin and rosuvastatin interfered with MRP4 function inhibiting ATP-dependent cGMP (cyclic guanosine monophosphate) uptake into MRP4-containing vesicles, inhibited MRP4-mediated S1P transport in vitro and significantly attenuated endogenous S1P release from agonist-activated platelet ex vivo. These data suggest that release of S1P from platelets depends on MRP4 and statins can interfere with this transport process. Potentially, this may be relevant for the pleiotropic anti-inflammatory effects of statins and their effect on modulating atherothrombosis.

SummaryThe multidrug resistance protein 4 (MRP4/ABCC4) has been identified as an important transporter for signalling molecules including cyclic nucleotides and several lipid mediators in platelets and may thus represent a novel target to interfere with platelet function. Besides its localisation in the plasma membrane, MRP4 has been also detected in the membrane of dense granules in resting platelets. In polarised cells it is localised at the basolateral or apical plasma membrane. To date, the mechanism of MRP4 trafficking has not been elucidated; protein interactions may regulate both the localisation and function of this transporter. We approached this issue by searching for interacting proteins by in vitro binding assays, followed by immunoblotting and mass spectrometry, and by visualising their co-localisation in platelets and haematopoietic cells. We identified the PDZ domain containing scaffold proteins ezrin-binding protein 50 (EBP50/NHERF1), postsynaptic density protein 95 (PSD95), and sorting nexin 27 (SNX27), but also the adaptor protein complex 3 subunit β3A (AP3B1) and the heat shock protein HSP90 as putative interaction partners of MRP4. The knockdown of SNX27, PSD95, and AP3B1 by siRNA in megakaryoblastic leuk aemia cells led to a redistribution of MRP4 from intracellular structures to the plasma membrane. Inhibition of HSP90 led to a diminished expression and retention of MRP4 in the endoplasmic reticulum. These results indicate that MRP4 localisation and function are regulated by multiple protein interactions. Changes in the adaptor proteins can hence lead to altered localisation and function of the transporter.Supplementary Material to this article is available at www.thrombosis-online.com.

Important antimalarial drugs, including quinolines, act against blood schizonts by interfering with hemoglobin metabolism. To reach their site of action, these compounds have to cross the plasma membrane of red blood cells (RBCs). Organic cation transporters (OCTs) and organic anion transporting polypeptides (OATPs) are important uptake transporters and interesting candidates for local drug transport. We therefore studied their interaction with antimalarial compounds (quinine, chloroquine, mefloquine, pyrimethamine, artemisinin, and artesunate) and characterized the expression of OATP1A2 and OATP2B1 in RBCs. Competition assays using transporter-overexpressing Madin-Darby canine kidney (MDCKII) cells and the model substrate estrone-3-sulfate identified quinine and chloroquine as potent inhibitors of OATP1A2 function (IC50 quinine: 0.7 ± 1.2 µM; chloroquine: 1.0 ± 1.5 µM), but no or only moderate effects were observed for OATP2B1. Subsequently, quinine was identified as a substrate of OATP1A2 (Km 23.4 µM). The OATP1A2-mediated uptake was sensitive to the OATP1A2-specific inhibitor naringin. Both OATPs were expressed in human RBCs, and ex vivo transport studies demonstrated naringin-sensitive accumulation of quinine in these cells (60 pmol versus 38 pmol/5 × 10(5) RBCs). Additional transport studies using OCT1-3 and organic cation transporter novel type 1 (OCTN1) indicated only significant quinine uptake by OCT1, which was not detected in RBCs. In conclusion, our data demonstrate expression of OATP2B1 and OATP1A2 in RBCs as well as OATP1A2-mediated uptake of quinine. Therefore, modulation of OATP1A2 function may affect quinine uptake into erythrocytes.

The solute carrier (SLC) group of membrane transport proteins includes about 400 members organized into more than 50 families. The SLC family that comprises nucleoside-sugar transporters is referred to as SLC35. One of the members of this family is SLC35F1. The function of SLC35F1 is still unknown; however, recent studies demonstrated that SLC35F1 mRNA is highly expressed in the brain and in the kidney. Therefore, we examine the distribution of Slc35f1 protein in the murine forebrain using immunohistochemistry. We could demonstrate that Slc35f1 is highly expressed in the adult mouse brain in a variety of different brain structures, including the cortex, hippocampus, amygdala, thalamus, basal ganglia, and hypothalamus. To examine the possible roles of Slc35f1 and its subcellular localization, we used an in vitro glioblastoma cell line expressing Slc35f1. Co-labeling experiments were performed to reveal the subcellular localization of Slc35f1. Our results indicate that Slc35f1 neither co-localizes with markers for the Golgi apparatus nor with markers for the endoplasmic reticulum. Time-lapse microscopy of living cells revealed that Slc35f1-positive structures are highly dynamic and resemble vesicles. Using super-resolution microscopy, these Slc35f1-positive spots clearly co-localize with the recycling endosome marker Rab11.

Evidence-based medicine & limitations of guidelines In the last century, fundamental developments in the sciences have led to important improvements in differential diagnostics and treatment of many diseases. Evidence-based medicine (EBM) provided a conceptual framework for the extraction and condensation of relevant knowledge from the immense body of data that has increasingly become a challenge to clinicians and scientists. In EBM, randomized controlled trials in defined study populations that applied strict inclusion and exclusion criteria were deemed the best research evidence, and systematic reviews were applied to extract valid, clinically relevant information [1]. Hence, EBM marked a major progress from an individual experience-driven practice of medicine to empirically founded, rational medical decision-making that is research driven. Reasoned EBM is operationalized as diagnostic and therapeutic guidelines for clinical practice, including definition, classification, diagnostics, treatment, management and monitoring of a disease.

Recently research provides evidence that blood metabolite profiles predicted type 2 diabetes. We aimed to assess the relation of urine metabolites measured via nuclear magnetic resonance spectroscopy with incident type 2 diabetes in a sample of 1353 men and 1356 women. Within 5 years, 87 men and 50 women developed diabetes. Five and 16 urine metabolites were associated with incident diabetes in men and women, respectively. Only three of these metabolites (glucose, lactate and glycine) were found in both sexes. In women, e.g. acetate, carnitine, N,N-dimethylglycine, trigonelline, 3-hydroxyisovalerate, alanine, formate, glycolate, trimethylamine N-oxide and tau-methylhistidine were positively related with diabetes. Receiver operating characteristic (ROC) analysis revealed that compared with a standard model, a model additionally adjusted for urine glucose, trigonelline and trimethylamine N-oxide levels showed a better discrimination between incident diabetes cases and non-cases in women (AUC = 0.874 and 0.903, p = 0.019). In men, valine and 4-hydroxyphenylacetate were found as markers of diabetes. However, ROC analysis did not reveal any improvement in discrimination based on urine metabolites. In conclusion, we confirmed the potential of metabolomics to assess the risk of type 2 diabetes and detected pronounced sex differences. Moreover, we demonstrated the practicability of spot urine samples as potential non-invasive diabetes screening approach.

The clinical efficiency of the highly potent antitumor agent doxorubicin is limited by cardiotoxic effects. In a murine doxorubicin cardiotoxicity model, increased endothelin-1 (ET-1) expression and cardioprotective effects of the dual ET-1 blocker bosentan were demonstrated. To date it is unclear if combined blocking of endothelin A/B receptors is necessary or whether selective inhibition of one of the ET-1 receptors is sufficient for the observed cardioprotection. Therefore, we investigated the impact of dual (bosentan) and single endothelin receptor antagonism through sitaxentan (receptor A blocker) or BQ788 (receptor B blocker) in a murine doxorubicin cardiotoxicity model (C57BL/6N). Simultaneous administration of each endothelin receptor antagonist (ERA) with doxorubicin resulted in a significantly improved hemodynamic performance in comparison to the impaired cardiac function in control mice with bosentan being most effective but closely followed by sitaxentan and also BQ788. This cardioprotection was not caused by diminished doxorubicin levels in heart since the doxorubicin content in cardiac tissue was not altered by ERAs significantly. However, whole transcript expression profiling showed partly different effects of the ERAs on doxorubicin-modulated cardiac gene expression of genes involved in signal transduction (e.g. Stat3, Pim1, Akt1, Plcb2), fibrosis (e.g. Myl4), energy production (e.g. Ant1) or oxidative stress (e.g. Aox1). Furthermore, doxorubicin-mediated gene regulations were verified in the murine cardiomyocyte model HL-1 showing partly reversed expression patterns after co-administration of the ERAs. In summary, our results demonstrate strong cardioprotective effects of blocking ET-1 receptors against the doxorubicin-related cardiomyopathy and provide evidence to potential underlying signaling pathways.

The anthracycline-mediated cardiotoxicity is still not completely understood. To examine the impact of cholesterol metabolism and transport in this context, cholesterol and oxysterol levels as well as the expression of the cholesterol transporters ABCA1 and ABCG1 were analyzed in doxorubicin-treated HL-1 murine cardiomyocytes as well as in mouse model for acute doxorubicin-induced cardiotoxicity. Doxorubicin-treated HL-1 cells exhibited enhanced cholesterol (153±20% of control), oxysterol (24S-hydroxycholesterol: 206±29% of control) and cholesterol precursor levels (lathosterol: 122±12% of control; desmosterol: 188±10% of control) indicating enhanced cholesterol synthesis. Moreover, abca1 and abcg1 were upregulated on mRNA, protein and functional level caused by a doxorubicin-mediated activation of the nuclear receptor LXR. In addition, the oxysterols not only induced the abca1 and abcg1 in HL-1 cells but also enhanced the expression of endothelin-1 and transforming growth factor-β, which have already been identified as important factors in doxorubicin-induced cardiotoxicity. These in vitro findings were verified in a murine model for acute doxorubicin-induced cardiotoxicity, demonstrating elevated cardiac (2.1±0.2vs. 3.6±1.0ng/mg) and systemic cholesterol levels (105.0±8.4vs. 130.0±4.3mg/dl), respectively, as well as enhanced oxysterol levels such as cardiac 24S-hydroxycholesterol (2.1±0.2vs. 3.6±1.0ng/mg). In line with these findings cardiac mRNA expression of abca1 (303% of control) and abcg1 (161% of control) was induced. Taken together, our data demonstrate enhanced cholesterol and oxysterol levels by doxorubicin, resulting in a LXR-dependent upregulation of abca1 and abcg1. In this context, the cytotoxic effects of oxysterols and their impact on cardiac gene expression should be considered as an important factor in doxorubicin-induced cardiotoxicity.

Renal tubular handling of urate is realized by a network of uptake and efflux transporters, including members of drug transporter families such as solute carrier proteins and ATP-binding cassette transporters. Solute carrier family 2, member 9 (SLC2A9), is one key factor of this so called “urate transportosome.” The aim of the present study was to understand the transcriptional regulation of SLC2A9 and to test whether identified factors might contribute to a coordinated transcriptional regulation of the transporters involved in urate handling. In silico analysis and cell-based reporter gene assays identified a hepatocyte nuclear factor (HNF)4α-binding site in the promoter of SLC2A9 isoform 1, whose activity was enhanced by transient HNF4α overexpression, whereas mutation of the binding site diminished activation. HNF4α overexpression induced endogenous SLC2A9 expression in vitro. The in vivo role of HNF4α in the modulation of renal SLC2A9 gene expression was supported by findings of quantitative real-time RT-PCR analyses and chromatin immunoprecipitation assays. Indeed, mRNA expression of SLC2A9 and HNF4α in human kidney samples was significantly correlated. We also showed that in renal clear cell carcinoma, downregulation of HNF4α mRNA and protein expression was associated with a significant decline in expression of the transporter. Taken together, our data suggest that nuclear receptor family member HNF4α contributes to the transcriptional regulation of SLC2A9 isoform 1. Since HNF4α has previously been assumed to be a modulator of several urate transporters, our findings support the notion that there could be a transcriptional network providing synchronized regulation of the functional network of the urate transportosome.

Multidrug resistance protein 4 (MRP4/ABCC4) has been established as an independent regulator of cyclic AMP (cAMP) levels particularly in vascular smooth muscle cells and in hematopoietic cells. Here, we assessed whether cAMP in turn regulates MRP4. A significant upregulation of MRP4 mRNA and protein by long-term treatment with cAMP-enhancing agents was observed in HeLa cells, smooth muscle cells, and megakaryoblastic leukemia M07e cells. This upregulation was not affected by inhibition of protein kinase A, but could be reverted by inhibitors and siRNA of an alternative cAMP-signaling route involving exchange proteins activated by cyclic AMP (EPAC) and mitogen-activated protein kinases. A selective EPAC activator could equally induce MRP4. The transcriptional regulation was confirmed in a luciferase reporter gene assay using a vector containing a 1494-bp fragment of the promoter region of the MRP4/ABCC4 gene. Our results suggest that enhanced cAMP levels upregulate MRP4 expression, which can result in increased cAMP efflux.

Statins, frequently prescribed in lipid-lowering therapies, seem to have additional beneficial effects on periodontitis and tooth loss. If this is true, then chronic treatment with statins should also result in diminished tooth loss as a long-term response.A 5-year population-based follow-up study of tooth loss was performed comparing participants treated with statins (n = 134) with those not on the drugs (Study of Health in Pomerania). Negative binomial regression models were used to analyze the count variable of the outcome, including risk factors for tooth loss and measures of cholesterol metabolism.When adjusted for age and sex, statins were associated with reduced tooth loss during the follow-up period (incidence risk ratio [IRR] = 0.70, 95% confidence interval [CI] = 0.50 to 0.99, P = 0.04). When additionally adjusted for risk factors of periodontal breakdown, IRR was 0.72 (95% CI = 0.52 to 1.01). There was significant interaction with low-density lipoprotein cholesterol (LDL-c) at baseline. After stratification by LDL-c, statins were associated with reduced tooth loss, resulting in IRR = 0.89 (95% CI = 0.44 to 1.83) and 0.64 (95% CI = 0.43 to 0.95), P = 0.03, at LDL-c concentrations ≤100 mg/dL and100 mg/dL (2.58 mmol/L), respectively. The data also showed reduced tooth loss associated with the 5-year reduction in LDL-c levels on a mmol/L basis and independently of statins (IRR = 0.87, 95% CI = 0.80 to 0.96, P = 0.004).Long-term treatment with systemically administered statins may have the beneficial effect of protecting against tooth loss.

Molecular transporters that are expressed in brain, especially at the blood-brain barrier (BBB), are increasingly recognized as possible therapeutic targets in the treatment of neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Some ATP-binding cassette (ABC) transporters, particularly P-glycoprotein (ABCB1), MRP1 (ABCC1) and BCRP (ABCG2), have been implicated in the clearance of neurotoxic polypeptides that characteristically accumulate in the brain, such as amyloid-β (Aβ) peptides in Alzheimer's disease. Several lines of evidence also implicate lipid transporters of the A-branch of ABC transporters in pathogenesis. Induction of transporters via the activation of specific nuclear receptors may represent a novel approach to restoring diminished BBB function. On the other hand, transporters in the brain capillary endothelium regulate the permeation of therapeutic compounds into the brain. In addition to the export pumps that limit brain entry of exogenous substances, SLC-type uptake transporters, especially of the OCT (SLC22A) family, are of potential relevance in that they mediate not only the uptake of several drugs used for the treatment of neurodegenerative diseases, but also of certain neurotoxins. Here, we summarize recent findings and novel strategies targeting transporters to reduce brain pathology or to improve drug therapy.

Auto-antibodies against cardiac proteins have been described in patients with dilated cardiomyopathy. Antibodies against the C-terminal part of KChIP2 (anti-KChIP2 [C-12]) enhance cell death of rat cardiomyocytes. The underlying mechanisms are not fully understood. Therefore, we wanted to explore the mechanisms responsible for anti-KChIP2-mediated cell death. Rat cardiomyocytes were treated with anti-KChIP2 (C-12). KChIP2 RNA and protein expressions, nuclear NF-κB, mitochondrial membrane potential Δψm, caspase-3 and -9 activities, necrotic and apoptotic cells, total Ca2+ and K+ concentrations, and the effects on L-type Ca2+ channels were quantified. Anti-KChIP2 (C-12) induced nuclear translocation of NF-κB. Anti-KChIP2 (C-12)-treatment for 2 h significantly reduced KChIP2 mRNA and protein expression. Anti-KChIP2 (C-12) induced nuclear translocation of NF-κB after 1 h. After 6 h, Δψm and caspase-3 and -9 activities were not significantly changed. After 24 h, anti-KChIP2 (C-12)-treated cells were 75 ± 3% necrotic, 2 ± 1% apoptotic, and 13 ± 2% viable. Eighty-six ± 1% of experimental buffer-treated cells were viable. Anti-KChIP2 (C-12) induced significant increases in total Ca2+ (plus 11 ± 2%) and K+ (plus 18 ± 2%) concentrations after 5 min. Anti-KChIP2 (C-12) resulted in an increased Ca2+ influx through L-type Ca2+ channels. In conclusion, our results suggest that anti-KChIP2 (C-12) enhances cell death of rat cardiomyocytes probably due to necrosis. J. Cell. Biochem. 115: 678–689, 2014. © 2013 Wiley Periodicals, Inc.

ObjectivesThis study sought to evaluate the role of protease-activated receptor-2 (PAR2) in coxsackievirus B3 (CVB3)–induced myocarditis.BackgroundAn infection with CVB3 leads to myocarditis. PAR2 modulates the innate immune response. Toll-like receptor-3 (TLR3) is crucial for the innate immune response by inducing the expression of the antiviral cytokine interferon-beta (IFNβ).MethodsTo induce myocarditis, wild-type (wt) and PAR2 knockout (ko) mice were infected with 105 plaque-forming units CVB3. Mice underwent hemodynamic measurements with a 1.2-F microconductance catheter. Wt and PAR2ko hearts and cardiac cells were analyzed for viral replication and immune response with plaque assay, quantitative polymerase chain reaction, Western blot, and immunohistochemistry.ResultsCompared with wt mice, PAR2ko mice and cardiomyocytes exhibited a reduced viral load and developed no myocarditis after infection with CVB3. Hearts and cardiac fibroblasts from PAR2ko mice expressed higher basal levels of IFNβ than wt mice did. Treatment with CVB3 and polyinosinic:polycytidylic acid led to higher IFNβ expression in PAR2ko than in wt fibroblasts and reduced virus replication in PAR2ko fibroblasts was abrogated by neutralizing IFNβ antibody. Overexpression of PAR2 reduced the basal IFNβ expression. Moreover, a direct interaction between PAR2 and Toll-like receptor 3 was observed. PAR2 expression in endomyocardial biopsies of patients with nonischemic cardiomyopathy was positively correlated with myocardial inflammation and negatively with IFNβ expression and left ventricular ejection fraction.ConclusionsPAR2 negatively regulates the innate immune response to CVB3 infection and contributes to myocardial dysfunction. The antagonism of PAR2 is of therapeutic interest to strengthen the antiviral response after an infection with a cardiotropic virus.

Objective Data mining represents an alternative approach to identify new predictors of multifactorial diseases. This work aimed at building an accurate predictive model for incident hypertension using data mining procedures. Methods The primary study population consisted of 1605 normotensive individuals aged 20-79 years with 5-year follow-up from the population-based study, that is the Study of Health in Pomerania (SHIP). The initial set was randomly split into a training and a testing set. We used a probabilistic graphical model applying a Bayesian network to create a predictive model for incident hypertension and compared the predictive performance with the established Framingham risk score for hypertension. Finally, the model was validated in 2887 participants from INTER99, a Danish community-based intervention study. Results In the training set of SHIP data, the Bayesian network used a small subset of relevant baseline features including age, mean arterial pressure, rs16998073, serum glucose and urinary albumin concentrations. Furthermore, we detected relevant interactions between age and serum glucose as well as between rs16998073 and urinary albumin concentrations [area under the receiver operating characteristic (AUC 0.76)]. The model was confirmed in the SHIP validation set (AUC 0.78) and externally replicated in INTER99 (AUC 0.77). Compared to the established Framingham risk score for hypertension, the predictive performance of the new model was similar in the SHIP validation set and moderately better in INTER99. Conclusion Data mining procedures identified a predictive model for incident hypertension, which included innovative and easy-to-measure variables. The findings promise great applicability in screening settings and clinical practice.

Aim To identify loci associated with chronic periodontitis through a genome-wide association study (GWAS). Materials and Methods A GWAS was performed in 4032 individuals of two independent cross-sectional studies of West Pomerania (SHIP n = 3365 and SHIP-TREND n = 667) with different periodontal case definitions. Samples were genotyped with the Affymetrix Genome-Wide Human SNP Array 6.0 or the Illumina Human Omni 2.5 array. Imputation of the HapMap as well as the 1000 Genome-based autosomal and X-chromosomal genotypes and short insertions and deletions (INDELs) was performed in both cohorts. Finally, more than 17 million SNPs and short INDELs were analysed. Results No genome-wide significant associations were found for any periodontitis case definition, regardless of whether individuals aged >60 years where excluded or not. Despite no single SNP association reached genome-wide significance, the proportion of variance explained by additive effects of all common SNPs was around 23% for mean proximal attachment loss. Excluding subjects aged >60 years increased the explained variance to 34%. Conclusions No single SNPs were found to be genome-wide significantly associated with chronic periodontitis in this study.

The primary goals of personalized medicine are to optimize diagnostic and treatment strategies by tailoring them to the specific characteristics of an individual patient. In this Review, we summarize basic concepts and methods of personalizing cardiovascular medicine. In-depth characterization of study participants and patients in general practice using standardized methods is a pivotal component of study design in personalized medicine. Standardization and quality assurance of clinical data are similarly important, but in daily practice imprecise definitions of clinical variables can reduce power and introduce bias, which limits the validity of the data obtained as well as their potential clinical applicability. Changes in statistical methods with personalized medicine include a shift from dichotomous outcomes towards continuously measured variables, predictive modelling, and individualized medical decisions, subgroup analyses, and data-mining strategies. A variety of approaches to personalized medicine exist in cardiovascular research and clinical practice that might have the potential to individualize diagnostic and therapeutic procedures. For some of the emerging methods, such as data mining, the most-efficient way to use these tools is not yet fully understood. In addition, the predictive models-although promising-are far from mature, and are likely to be greatly improved by using available large-scale data sets.

Drug-eluting stents (DES) have revolutionized the treatment of coronary artery blockage by tremendously reducing the rate of in-stent restenosis and the necessity of repeat revascularization compared to bare-metal stents. They are also gaining increasing importance in other medical fields such as the treatment of certain localized tumors and in glaucoma therapy. DES generally contain most potent drugs, e.g. immunosuppressants or cytostatics, which are supposed to be released in a well controlled manner over time spans which are chosen according to disease progression. Typically, this means that fairly small amounts of drug are released over long periods of time. Therefore, quantification of in vivo plasma levels is often not feasible. Due to this limitation and the fact that tissue levels cannot be determined in humans, in vitro dissolution testing is one of the most powerful tools to gain insight into the release behaviour of DES. This article focuses on the methods for in vitro dissolution testing of DES which are available up to date and highlights the specific characteristics of drug release from stents arising from the composition and the in vivo localization of the dosage form.

Beyond their originally sole mechanical function, current drug-eluting stents (DES) implement the concept of local drug delivery for the re-opening of stenotic arterial vessels, and for prevention of in-stent restenosis as one of the major limitations of conventional bare metal stents (BMS). Current DES consist of a permanent metallic stent platform and an active agent being released from a drug-incorporated polymer coating or a porous stent surface. Although DES have impressively demonstrated their capability of reducing in-stent restenosis, their safety remains under debate due to potential risks, such as delayed healing, late thrombosis and hypersensitivity demanding further development. Current advancements in the stent design address the stent platform, the pharmacologically active substance and/or the drug carrier. For instance, novel biocompatible absorbable stent platforms and drug carriers are developed and novel drugs with a differential effect on vascular endothelial and smooth muscle cells, providing efficient inhibition of muscle cells without altering the endothelial cell function, are identified. Moreover, biofunctionalization of the stent’s surface with capture molecules for endothelial progenitor cells are under investigation in order to achieve an in situ endothelialization of the implant. In this context, this review paper discusses the current advances in coronary stent technology with a special focus on novel stent platforms, drugs and stent coatings for the prevention of restenosis and improvement of biocompatibility.

Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways. J.T. and P.H. are consultants for Servier. J.C. received research grants and honoraria from Servier. K.S. obtained research support from Boehringer Ingelheim. The remaining authors declared no competing financial interests.

DHEA is the major precursor of human sex steroid synthesis and is inactivated via sulfonation to DHEAS. A previous genome-wide association study related the single nucleotide polymorphism (SNP) rs2637125, located near the coding region of DHEA sulfotransferase, SULT2A1, to serum DHEAS concentrations. However, the functional relevance of this SNP with regard to DHEA sulfonation is unknown. Using data from 3300 participants of the population-based cohort Study of Health in Pomerania, we identified 43 individuals being homozygote for the minor allele of the SNP rs2637125 (AA) and selected two sex- and age-matched individuals with AG and GG genotype (n=172) respectively. Steroid analysis including measurement of serum DHEA and DHEAS was carried out by liquid chromatography/mass spectrometry, employing steroid oxime analysis for enhancing the sensitivity of DHEA detection. We applied quantile regression models to compare median hormone levels across SULT2A1 genotypes. Median comparisons by SULT2A1 genotype (AA vs AG and GG genotypes respectively) showed no differences in the considered hormones including DHEAS, DHEA, androstenedione, as well as cortisol and cortisone concentrations. SULT2A1 genotype also had no effect on the DHEA/DHEAS ratio. Sex-stratified analyses, as well as alternative use of the SULT2A1 SNP rs182420, yielded similar negative results. Genetic variants of SULT2A1 do not appear to have an effect on individual DHEA and DHEAS concentrations or the DHEA/DHEAS ratio as a marker of DHEA sulfonation capacity.

An early response to high arterial pressure is the development of cardiac hypertrophy. Functional and transcriptional regulation of ion channels and Ca(2+) handling proteins are involved in this process but the relative contribution of each is unclear. In this study, we investigated the expression of genes involved in action potential generation and Ca(2+) homeostasis of cardiomyocytes in hypertensive cyp1a1ren-2 transgenic rats. In this model, the transgene prorenin was induced by indole-3-carbinol for 2 weeks allowing the induction of hypertension. Electrophysiological recordings from cardiomyocytes of hypertensive rats revealed a slight increase in membrane capacitance consistent with cellular hypertrophy. L-type calcium current density was reduced by 30%. Left ventricles of hypertensive rats showed a significant increase in transcript and protein levels of the cation channel TRPC6 and FK506-binding protein, whereas levels of SERCA2 and voltage-dependent potassium channels K(v)4.2 and K(v)4.3 were found to be decreased. Further, a marked nuclear localization of the transcription factors GATA4 and NFATC4 was observed in cardiac tissue of hypertensive rats. The cyp1a1ren-2 transgenic rat thus appears to be a valid model to investigate early changes in cardiac hypertrophy. This study points to roles for TRPC6, FK506BP, SERCA2, K(v)4.2, and K(v)4.3 in the development of cardiac hypertrophy.

Item does not contain fulltext AIMS: Immunoadsorption with subsequent immunoglobulin G substitution (IA/IgG) represents a novel therapeutic approach in the treatment of dilated cardiomyopathy (DCM) which leads to the improvement of left ventricular ejection fraction (LVEF). However, response to this therapeutic intervention shows wide inter-individual variability. In this pilot study, we tested the value of clinical, biochemical, and molecular parameters for the prediction of the response of patients with DCM to IA/IgG. METHODS AND RESULTS: Forty DCM patients underwent endomyocardial biopsies (EMBs) before IA/IgG. In eight patients with normal LVEF (controls), EMBs were obtained for clinical reasons. Clinical parameters, negative inotropic activity (NIA) of antibodies on isolated rat cardiomyocytes, and gene expression profiles of EMBs were analysed. Dilated cardiomyopathy patients displaying improvement of LVEF (>/=20 relative and >/=5% absolute) 6 months after IA/IgG were considered responders. Compared with non-responders (n = 16), responders (n = 24) displayed shorter disease duration (P = 0.006), smaller LV internal diameter in diastole (P = 0.019), and stronger NIA of antibodies. Antibodies obtained from controls were devoid of NIA. Myocardial gene expression patterns were different in responders and non-responders for genes of oxidative phosphorylation, mitochondrial dysfunction, hypertrophy, and ubiquitin-proteasome pathway. The integration of scores of NIA and expression levels of four genes allowed robust discrimination of responders from non-responders at baseline (BL) [sensitivity of 100% (95% CI 85.8-100%); specificity up to 100% (95% CI 79.4-100%); cut-off value: -0.28] and was superior to scores derived from antibodies, gene expression, or clinical parameters only. CONCLUSION: Combined assessment of NIA of antibodies and gene expression patterns of DCM patients at BL predicts response to IA/IgG therapy and may enable appropriate selection of patients who benefit from this therapeutic intervention.

To report the frequencies of potentially relevant incidental findings in the general adult population and to develop a protocol for their management in whole-body magnetic resonance imaging (wb-MRI).A total of 2,500 adult subjects (1,271 women, 1,229 men; mean age 53 years) from the population-based Study of Health in Pomerania underwent standardised wb-MRI. Additionally, 1,129 participants received contrast-enhanced cardiac MRI, 619 men received MR angiography and 544 women received MR mammography. Two independent residents performed first-line reading. A third reader resolved disagreements. An interdisciplinary advisory board decided about disclosure.There were 1,330 incidental findings of potential clinical relevance in 904 subjects (36.2 %). Nine findings (0.4 %) required immediate referral. In total, 1,052 findings (79.1 %) were confirmed by the advisory board and disclosed to 787 participants (31.5 %). The abdominal organs (6.8 %), the urinary tract (6.8 %) and the skeletal system (6.0 %) were affected most often. While 383 findings (36.4 %) were indicated as benign and 62 (5.9 %) as malignant, most abnormalities, 607 (57.7 %), were of an unclear nature.Potentially relevant incidental findings are very common in wb-MRI research but the nature of these findings remains unclear in most cases. This requires dedicated management to protect subjects' welfare and research integrity.

The clinical course of patients with dilated cardiomyopathy (DCM) varies from cardiac recovery to end stage heart failure. The etiology of this variability is largely unknown. In this study, we investigated the impact of coding polymorphisms of the innate immune protein Toll-like receptor 4 (TLR4) on left ventricular performance in patients with DCM. Two variants of TLR4 (rs4986790, TLR4 c.1187A→G, p.299D→G and rs4986791,TLR4 c.1487C→T, p.T399I) were investigated in 158 patients with DCM. Other reasons for heart failure were excluded by coronary angiography, myocardial biopsy, and echocardiography. Risk factors, age, gender, or treatment did not differ among the groups. At the follow-up evaluation (median 4.0-5.4 months), patients carrying the TLR4 wild type gene displayed cardiac recovery under intense medical heart failure therapy indexed by reduced left ventricular dilation, improved left ventricular ejection fraction, and reduced NT-probrain natriuretic peptide blood level when compared with the initial evaluation. In contrast, patients carrying both the rs4986790 and the rs4986791 variant showed significantly reduced improvement of left ventricular ejection fraction (p = 0.006) and left ventricular dilation (p = 0.015) at the follow-up evaluation when compared with carriers of the wild type gene under the same treatment conditions. In addition, NT-probrain natriuretic peptide level in carriers of both TLR4 variants did not change significantly at the follow up when compared with the first evaluation. Among patients with DCM, the presence of the TLR4 variants rs4986790 and rs4986791 predicts impaired cardiac recovery independently of medical treatment or cardiac risk factors.

Background/aims: The application of intranasal oxytocin enhances facial emotion recognition in normal subjects and in subjects with autism spectrum disorders (ASD). In addition, various features of social cognition have been associated with variants of the oxytocin receptor gene (OXTR). Therefore, we tested for associations between mind-reading, a measure for social recognition and OXTR polymorphisms. Methods: 76 healthy adolescents and young adults were tested for associations between OXTR rs53576, rs2254298, rs2228485 and mind-reading using the “Reading the Mind in the Eyes Test” (RMET). Results: After Bonferroni correction for multiple comparisons, rs2228485 was associated with the number of incorrect answers when subjects evaluated male faces (P =0.000639). There were also associations between OXTR rs53576, rs2254298 and rs2228485 and other RMET dimensions according to P

Nuclear receptors such as the constitutive androstane receptor (CAR) are central factors that link drug exposure to the activities of drug metabolism and elimination. In order to determine the in vivo effects of efavirenz, a CAR activator, the expression of target genes was determined in duodenal biopsies obtained from 12 healthy volunteers before treatment and after 10 days of treatment with efavirenz; concomitant administration of the cholesterol inhibitor ezetimibe produced no significant difference. However, in in vitro studies, efavirenz significantly increased CYP2B6 expression in several cell types, suggesting that the drug transactivates CAR. This hypothesis is supported by our findings that there is significant induction of CAR target genes in in vivo peripheral blood mononuclear cells (PBMCs) isolated from healthy volunteers treated with multiple doses of efavirenz. The impact of efavirenz on hepatic metabolism in vivo was confirmed by significant changes in plasma 4β-hydroxycholesterol and bilirubin levels and the area under the curve (AUC) of efavirenz. Induction of CYP2B6 mRNA expression correlated with the decrease in the AUC of efavirenz (r = 0.61; P = 0.036). Taken together, our results provide evidence that efavirenz exerts compartment-specific inductive capacity in vivo.

Platelets store signaling molecules (eg, serotonin and ADP) within their granules. Transporters mediate accumulation of these molecules in platelet granules and, on platelet activation, their translocation across the plasma membrane. The balance between transporter-mediated uptake and elimination of signaling molecules and drugs in platelets determines their intracellular concentrations and effects. Several members of the 2 major transporter families, ATP-binding cassette (ABC) transporters and solute carriers (SLCs), have been identified in platelets. An example of an ABC transporter is MRP4 (ABCC4), which facilitates ADP accumulation in dense granules. MRP4 is a versatile transporter, and various additional functions have been proposed, notably lipid mediator release and a role in aspirin resistance. Several other ABC proteins have been detected in platelets with functions in glutathione and lipid homeostasis. The serotonin transporter (SERT, SLC6A4) in the platelet plasma membrane represents a well-characterized example of the SLC family. Moreover, recent experiments indicate expression of OATP2B1 (SLCO2B1), a high affinity transporter for certain statins, in platelets. Changes in transporter localization and expression can affect platelet function and drug sensitivity. This review summarizes available data on the physiologic and pharmacologic role of transporters in platelets.

Activation of the immune system is a way for host tissue to defend itself against tumor growth. Hence, treatment strategies that are based on immunomodulation are on the rise. Conventional cytostatic drugs such as the anthracycline doxorubicin can also activate immune cell functions of macrophages and natural killer cells. In addition, cytotoxicity of doxorubicin can be enhanced by combining this drug with the cytokine interferon-γ (IFNγ). Although doxorubicin is one of the most applied cytostatics, the molecular mechanisms of its immunomodulation ability have not been investigated thoroughly. In microarray analyses of HeLa cells, a set of 19 genes related to interferon signaling was significantly over-represented among genes regulated by doxorubicin exposure, including signal transducer and activator of transcription (STAT) 1 and 2, interferon regulatory factor 9, N-myc and STAT interactor, and caspase 1. Regulation of these genes by doxorubicin was verified with real-time polymerase chain reaction and immunoblotting. An enhanced secretion of IFNγ was observed when HeLa cells were exposed to doxorubicin compared with untreated cells. IFNγ-neutralizing antibodies and inhibition of Janus tyrosine kinase (JAK)-STAT signaling [aurintricarboxylic acid (ATA), (E)-2-cyano-3-(3,4-dihydrophenyl)-N-(phenylmethyl)-2-propenamide (AG490), STAT1 small interfering RNA] significantly abolished doxorubicin-stimulated expression of interferon signaling-related genes. Furthermore, inhibition of JAK-STAT signaling significantly reduced doxorubicin-induced caspase 3 activation and desensitized HeLa cells to doxorubicin cytotoxicity. In conclusion, we demonstrate that doxorubicin induces interferon-responsive genes via IFNγ-JAK-STAT1 signaling and that this pathway is relevant for doxorubicin's cytotoxicity in HeLa cells. Immunomodulation is a promising strategy in anticancer treatment, so this novel mode of action of doxorubicin may help to further improve the use of this drug among different types of anticancer treatment strategies.

In conducting genome-wide association studies (GWAS), analytical approaches leveraging biological information may further understanding of the pathophysiology of clinical traits. To discover novel associations with estimated glomerular filtration rate (eGFR), a measure of kidney function, we developed a strategy for integrating prior biological knowledge into the existing GWAS data for eGFR from the CKDGen Consortium. Our strategy focuses on single nucleotide polymorphism (SNPs) in genes that are connected by functional evidence, determined by literature mining and gene ontology (GO) hierarchies, to genes near previously validated eGFR associations. It then requires association thresholds consistent with multiple testing, and finally evaluates novel candidates by independent replication. Among the samples of European ancestry, we identified a genome-wide significant SNP in FBXL20 (P = 5.6 × 10(-9)) in meta-analysis of all available data, and additional SNPs at the INHBC, LRP2, PLEKHA1, SLC3A2 and SLC7A6 genes meeting multiple-testing corrected significance for replication and overall P-values of 4.5 × 10(-4)-2.2 × 10(-7). Neither the novel PLEKHA1 nor FBXL20 associations, both further supported by association with eGFR among African Americans and with transcript abundance, would have been implicated by eGFR candidate gene approaches. LRP2, encoding the megalin receptor, was identified through connection with the previously known eGFR gene DAB2 and extends understanding of the megalin system in kidney function. These findings highlight integration of existing genome-wide association data with independent biological knowledge to uncover novel candidate eGFR associations, including candidates lacking known connections to kidney-specific pathways. The strategy may also be applicable to other clinical phenotypes, although more testing will be needed to assess its potential for discovery in general.

Background: Impaired vascular compliance is associated with cardiovascular mortality. The effects of heart rate on vascular compliance are unclear. Therefore, we characterized effects of heart rate reduction (HRR) by I(f) current inhibition on aortic compliance and underlying molecular mechanisms in apolipoprotein E-deficient (ApoE–/–) mice. Methods: ApoE–/– mice fed a high-cholesterol diet and wild-type (WT) mice were treated with ivabradine (20 mg/kg/d) or vehicle for 6 weeks. Compliance of the ascending aorta was evaluated by MRI. Results: Ivabradine reduced heart rate by 113 ± 31 bpm (∼19%) in WT mice and by 133 ± 6 bpm (∼23%) in ApoE–/– mice. Compared to WT controls, ApoE–/– mice exhibited reduced distensibility and circumferential strain. HRR by ivabradine increased distensibility and circumferential strain in ApoE–/– mice but did not affect both parameters in WT mice. Ivabradine reduced aortic protein and mRNA expression of the angiotensin II type 1 (AT1) receptor and reduced rac1-GTPase activity in ApoE–/– mice. Moreover, membrane translocation of p47phox was inhibited. In ApoE–/– mice, HRR induced anti-inflammatory effects by reduction of aortic mRNA expression of IL-6, TNF-alpha and TGF-beta. Conclusion: HRR by ivabradine improves vascular compliance in ApoE–/– mice. Contributing mechanisms include downregulation of the AT1 receptor, attenuation of oxidative stress and modulation of inflammatory cytokine expression.

Magnesium-based bioabsorbable cardiovascular stents have been developed to overcome limitations of permanent metallic stents, such as late stent thrombosis. During stent degradation, endothelial and smooth muscle cells will be exposed to locally high magnesium concentrations with yet unknown physiological consequences. Here, we investigated the effects of elevated magnesium concentrations on human coronary artery endothelial and smooth muscle cell (HCAEC, HCASMC) growth and gene expression. In the course of 24 h after incubation with magnesium chloride solutions (1 or 10 mM) intracellular magnesium level in HCASMC raised from 0.55 ± 0.25 mM (1 mM) to 1.38 ± 0.95 mM (10 mM), while no increase was detected in HCAEC. Accordingly, a DNA microarray-based study identified 69 magnesium regulated transcripts in HCAEC, but 2172 magnesium regulated transcripts in HCASMC. Notably, a significant regulation of various growth factors and extracellular matrix components was observed. In contrast, viability and proliferation of HCAEC were increased at concentrations of up to 25 mM magnesium chloride, while in HCASMC viability and proliferation appeared to be unaffected. Taken together, our data indicate that magnesium halts smooth muscle cell proliferation and stimulates endothelial cell proliferation, which might translate into a beneficial effect in the setting of stent associated vascular injury.

Common risk factors of periodontitis and cardiovascular diseases fuel the debate on interrelationships between them. The aim is to prove whether statins may influence periodontal parameters by affecting either of these factors. Out of the 4,290 subjects of SHIP (Study of Health in Pomerania), we included subjects aged >30 years (219 with statins, 2937 without) and excluded edentulous. We determined periodontal measures, cholesterol fractions, and inflammation markers. Statin use and periodontal risk factors were assessed. Gingival plaque and periodontal attachment loss were associated with systemic LDL cholesterol (P<0.001) and C-reactive protein CRP (P=0.019) revealing interaction with statin use. When adjusted for age, sex, smoking, diabetes, education, and dental service, statins were identified as effect modifiers abolishing the relationship between attachment loss and LDL and between gingival plaque and LDL (interactions P<0.001). No statin-related interaction was detected with increase in CRP. The interaction supports the view of inter-relationships between periodontal and systemic inflammatory mediators.

Doxorubicin is a frequently used anticancer drug, but its use is restricted due to the occurrence of severe side effects, namely strong cardiotoxicity. It is known from cancer cells that doxorubicin enhanced the expression of its efflux pump P-glycoprotein (P-gp), which may modulate local drug concentrations. We therefore studied the cardiac expression of P-gp in doxorubicin-treated mice. Mice were treated with doxorubicin, and P-gp expression was studied after 1, 3, and 5 days. Thereby, we could show a significant upregulation of abcb1a (162 ± 15% of control) and abcb1b (418 ± 110% of control) mRNA transcripts after 3 days. On protein level, western blot analysis and immunofluorescence staining revealed a similar finding 5 days after doxorubicin administration. In addition, these results could be confirmed by in vitro models using primary rat cardiomyocytes and the murine cardiomyocyte-like HL-1 cells. Besides an enhanced mRNA and protein expression, doxorubicin-treated HL-1 cells also demonstrated an enhanced P-gp function as assessed by a daunorubicin accumulation assay. Our in vivo and in vitro results demonstrate a cardiac upregulation of P-gp in doxorubicin-treated mice on expression and functional level. This finding may be relevant for cardiac tissue concentrations of P-gp substrates and may represent a mechanism in cardiac self-protection against xenobiotics. © 2011 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:3951–3958, 2011

Up to 50 % of patients with chronic diseases do not take their medication regularly. Poor adherence to drug therapy is associated with higher morbidity and mortality. A selective literature search using the terms adherence, compliance, concordance, persistence, medication management, and pharmaceutical care was performed. Evidence for improving adherence has been provided for the following principles: individual counselling of patients and care givers, medication management including simplifying dosing and use of combination tablets as well as the use of individual unit doses, e. g. blister cards. The effectiveness has only been shown for the duration of the interventions. The improvement of medication adherence represents an area of research with high impact on outcomes and cost. Measures to improve adherence may be as important as the development of novel therapies. However, prospective clinical evaluations with clinical endpoints are missing especially for the German health care system in order to develop recommendations for clinical practice. Joint efforts of physicians and pharmacists are needed.

In this article, two different scientific approaches to personalized medicine are compared. Biorepository at Vanderbilt University (BioVU) is a genomic biorepository at Vanderbilt University Medical Center in Nashville, TN, USA. Genetic biosamples are collected from leftover clinical blood samples; medical information is derived from an electronic medical records. Greifswald Approach to Individualized Medicine is a research resource at the University of Greifswald, Germany, comprised of clinical records combined with biosamples collected for research. We demonstrate that although both approaches are based on the collection of clinical data and biosamples, different legal milieus present in the USA and Germany as well as slight differences in scientific goals have led to different ‘ethical designs’. While BioVU can successfully operate with an ‘opt-out’ mechanism, an informed consent-based ‘opt-in’ model is indispensable to allow GANI_MED to reach its scientific goals.

The delivery of clarithromycin (CRL) to its site of action in bronchial/alveolar epithelial cells (EC), bronchial epithelial lining fluid (ELF), and bronchoalveolar lavage cells (BALC) may be influenced by CYP3A4 and the drug transporters, ATP-binding cassette (ABC) B1 and ABCC2 and organic anion-transporting polypeptides (OATPs), which can be modulated and/or up-regulated via the nuclear pregnane X receptor (PXR) by rifampicin (RIF). Therefore, we evaluated the disposition and pulmonary distribution of CLR (7.5 mg/kg b.i.d., 21 days) and expression of ABCB1, ABCC2, OATP1A2, and OATP2B1 in EC and BALC before and after comedication of RIF (10 mg/kg b.i.d., 11 days) in nine healthy foals (41–61 days, 115–159 kg) in which the genetic homology of drug transporters is close to that of their human analogs. After RIF comedication, relative bioavailability of CLR decreased by more than 90%. Concentrations in plasma (29.8 ± 26.3 versus 462 ± 368 ng/ml), ELF (0.69 ± 0.66 versus 9.49 ± 6.12 μg/ml), and BALC (10.2 ± 10.2 μg/ml 264 ± 375 μg/ml; all P < 0.05) were lowered drastically, whereas levels of the metabolite 14-hydroxyclarithromycin were not elevated despite higher 4β-hydroxycholesterol/cholesterol plasma concentration ratio, a surrogate for CYP3A4 induction. In the presence of CLR, ABCC2 and PXR mRNA contents were significantly and coordinately ( r 2 = 0.664, P < 0.001) reduced in BALC after RIF. In EC, mRNA expression of OATP1A2 increased but that of OATP2B1 decreased (both P < 0.05). RIF interrupts oral absorption and decreases CRL plasma levels below the minimal inhibitory concentration for eradication of Rhodococcus equi . Evidence that RIF influences the cellular uptake of CLR in bronchial cells and the PXR expression in BALC in the presence of high CLR concentrations exists.

We present a genome-wide association study of metabolic traits in human urine, designed to investigate the detoxification capacity of the human body. Using NMR spectroscopy, we tested for associations between 59 metabolites in urine from 862 male participants in the population-based SHIP study. We replicated the results using 1,039 additional samples of the same study, including a 5-year follow-up, and 992 samples from the independent KORA study. We report five loci with joint P values of association from 3.2 × 10(-19) to 2.1 × 10(-182). Variants at three of these loci have previously been linked with important clinical outcomes: SLC7A9 is a risk locus for chronic kidney disease, NAT2 for coronary artery disease and genotype-dependent response to drug toxicity, and SLC6A20 for iminoglycinuria. Moreover, we identify rs37369 in AGXT2 as the genetic basis of hyper-β-aminoisobutyric aciduria.

The recently introduced vessel-simulating flow-through cell offers new possibilities to examine the release from drug-eluting stents in vitro. In comparison with standard dissolution methods, the additional compartment allows for the examination of distribution processes and creates dissolution conditions which simulate the physiological situation at the site of implantation. It was shown previously that these conditions have a distinct influence on the release rate from the stent coating. In this work, different preparation techniques were developed to examine the spatial distribution within the compartment simulating the vessel wall. These methods allowed for the examination of diffusion depth and the distribution resulting in the innermost layer of the compartment simulating the vessel wall. Furthermore, the in vitro release and distribution examined experimentally were modelled mathematically using finite element (FE) methods to gain further insight into the release and distribution behaviour. The FE modelling employing the experimentally determined diffusion coefficients yielded a good general description of the experimental data. The results of the modelling also provided important indications that inhomogeneous coating layer thicknesses around the strut may result from the coating process which influence release and distribution behaviour. Taken together, the vessel-simulating flow-through cell in combination with FE modelling represents a unique method to analyse drug release and distribution from drug-eluting stents in vitro with particular opportunities regarding the examination of spatial distributions within the vessel-simulating compartment.

The aim of the study is to characterize the signal transduction leading to interstitial fibrosis in the pathogenesis of atrial fibrillation (AF) and atrial remodeling. Samples of the left atrial appendage (LA) from patients with AF showed higher collagen content (73 ± 5 vs. 38 ± 2 μg/mg protein) and 2.5-fold increased collagen crosslinking compared to patients with sinus rhythm (SR). Affymetrix-assays, RT-PCR and western Blot analysis revealed that LA of AF patients are characterized by increased lysyl oxidase (LOX) mRNA (218 ± 42%) and protein (253 ± 11%) expression. This was associated with increased expression of connective tissue growth factor (CTGF), fibronectin and Rac1 activity compared to SR. In neonatal cardiac fibroblasts, the Rac1 specific small molecule inhibitor NSC23766 prevented angiotensin II (AngII) induced upregulation of LOX (214 ± 16%) expression. Inhibition of CTGF by siRNA transfections completely inhibited AngII induced LOX expression. The LOX specific small molecule inhibitor BAPN prevented AngII and CTGF induced fibronectin expression. Left atria of transgenic mice with cardiac overexpression of Rac1 (RacET) that develop AF at high age exhibited upregulation of CTGF as well as LOX (187 ± 7%) and fibronectin (627 ± 146%) expression. Atria of RacET showed increased collagen content (28 ± 2 μg/mg protein) and crosslinking (10 ± 0.7) compared to wildtypes (20 ± 0.4 μg/mg protein; 5 ± 0.9). Left atrial myocardium of patients with atrial fibrillation is characterized by increased lysyl oxidase and fibronectin expression as well as collagen cross-linking. In cardiac fibroblasts, Rac1 GTPase mediates upregulation of fibronectin via LOX and CTGF. Inhibition of this signaling pathway may therefore represent a target for the prevention of fibrotic atrial remodeling.

Pharmacogenomics follows the concept of individualized medicine via targeted and tailored therapy for each patient. This is aided by current progress in human genome research that provided the basis to link genetic markers with pathogenesis and progression for the definition of new therapy options. To achieve this it will be necessary to show the validity and clinical utility of pharmacogenomic tests prior to release. The implementation of pharmacogenomics into clinical practise is a momentous future challenge that requires the establishment of interdisciplinary networks and professional organizations.

Insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-3 (IGFBP-3) are involved in cell replication, proliferation, differentiation, protein synthesis, carbohydrate homeostasis and bone metabolism. Circulating IGF-I and IGFBP-3 concentrations predict anthropometric traits and risk of cancer and cardiovascular disease. In a genome-wide association study of 10 280 middle-aged and older men and women from four community-based cohort studies, we confirmed a known association of single nucleotide polymorphisms in the IGFBP3 gene region on chromosome 7p12.3 with IGFBP-3 concentrations using a significance threshold of P < 5 × 10(-8) (P = 3.3 × 10(-101)). Furthermore, the same IGFBP3 gene locus (e.g. rs11977526) that was associated with IGFBP-3 concentrations was also associated with the opposite direction of effect, with IGF-I concentration after adjustment for IGFBP-3 concentration (P = 1.9 × 10(-26)). A novel and independent locus on chromosome 7p12.3 (rs700752) had genome-wide significant associations with higher IGFBP-3 (P = 4.4 × 10(-21)) and higher IGF-I (P = 4.9 × 10(-9)) concentrations; when the two measurements were adjusted for one another, the IGF-I association was attenuated but the IGFBP-3 association was not. Two additional loci demonstrated genome-wide significant associations with IGFBP-3 concentration (rs1065656, chromosome 16p13.3, P = 1.2 × 10(-11), IGFALS, a confirmatory finding; and rs4234798, chromosome 4p16.1, P = 4.5 × 10(-10), SORCS2, a novel finding). Together, the four genome-wide significant loci explained 6.5% of the population variation in IGFBP-3 concentration. Furthermore, we observed a borderline statistically significant association between IGF-I concentration and FOXO3 (rs2153960, chromosome 6q21, P = 5.1 × 10(-7)), a locus associated with longevity. These genetic loci deserve further investigation to elucidate the biological basis for the observed associations and clarify their possible role in IGF-mediated regulation of cell growth and metabolism.

Neurovascular dysfunction is an important component of Alzheimer's disease, leading to reduced clearance across the blood-brain barrier and accumulation of neurotoxicβ-amyloid (Aβ) peptides in the brain. It has been shown that the ABC transport protein P-glycoprotein (P-gp, ABCB1) is involved in the export of Aβfrom the brain into the blood. To determine whether Aβinfluences the expression of key Aβtransporters, we studied the effects of 1-day subcutaneous Aβ1-40 and Aβ1-42 administration via Alzet mini-osmotic pumps on P-gp, BCRP, LRP1, and RAGE expression in the brain of 90-day-old male FVB mice. Our results demonstrate significantly reduced P-gp, LRP1, and RAGE mRNA expression in mice treated with Aβ1-42 compared to controls, while BCRP expression was not affected. The expression of the four proteins was unchanged in mice treated with Aβ1-40 or reverse-sequence peptides. These findings indicate that, in addition to the age-related decrease of P-gp expression, Aβ1-42 itself downregulates the expression of P-gp and other Aβ-transporters, which could exacerbate the intracerebral accumulation of Aβand thereby accelerate neurodegeneration in Alzheimer's disease and cerebralβ-amyloid angiopathy.

Henry Volzke, y Dietrich Alte,1y Carsten Oliver Schmidt, Dorte Radke, Roberto Lorbeer, Nele Friedrich, Nicole Aumann, Katharina Lau, Michael Piontek, Gabriele Born, Christoph Havemann, Till Ittermann, Sabine Schipf, Robin Haring, Sebastian E Baumeister, Henri Wallaschofski, Matthias Nauck, Stephanie Frick, Andreas Arnold, Michael Junger, Julia Mayerle, Matthias Kraft, Markus M Lerch, Marcus Dorr, Thorsten Reffelmann, Klaus Empen, Stephan B Felix, Anne Obst, Beate Koch, Sven Glaser, Ralf Ewert, Ingo Fietze, Thomas Penzel, Martina Doren, Wolfgang Rathmann, Johannes Haerting, Mario Hannemann, Jurgen Ropcke, Ulf Schminke, Clemens Jurgens, Frank Tost, Rainer Rettig, Jan A Kors, Saskia Ungerer, Katrin Hegenscheid, Jens-Peter Kuhn, Julia Kuhn, Norbert Hosten, Ralf Puls, Jorg Henke, Oliver Gloger, Alexander Teumer, Georg Homuth, Uwe Volker, Christian Schwahn, Birte Holtfreter, Ines Polzer, Thomas Kohlmann, Hans J Grabe, Dieter Rosskopf, Heyo K Kroemer, Thomas Kocher, Reiner Biffar,17,y Ulrich John20y and Wolfgang Hoffmann1y

Background: Chronic kidney disease (CKD) and low serum total testosterone (TT) concentrations are independent predictors of mortality risk in the general population, but their combined potential for improved mortality risk stratification is unknown. Methods: We used data of 1,822 men from the population-based Study of Health in Pomerania followed- up for 9.9 years (median). The direct effects of kidney dysfunction (estimated glomerular filtration rate 2), albuminuria (urinary albumin-creatinine ratio ≧2.5 mg/mmol) and their combination (CKD) on all-cause and cardiovascular mortality were analyzed using multivariable Cox regression models. Serum TT concentrations below the age-specific 10th percentile (by decades) were considered low and were used for further risk stratification. Results: Kidney dysfunction (hazard ratio, HR, 1.40; 95% confidence interval, CI, 1.02–1.92), albuminuria (HR, 1.38; 95% CI, 1.06–1.79), and CKD (HR, 1.42; 95% CI, 1.09–1.84) were associated with increased all-cause mortality risk, while only kidney dysfunction (HR, 2.01; 95% CI, 1.21–3.34) was associated with increased cardiovascular mortality risk after multivariable adjustment. Men with kidney dysfunction and low TT concentrations were identified as high-risk individuals showing a more than 2-fold increased all-cause mortality risk (HR, 2.52; 95% CI, 1.08–5.85). Added to multivariable models, nonsignificant interaction terms suggest that kidney dysfunction and low TT are primarily additive rather than synergistic mortality risk factors. Conclusion: In the case of early loss of kidney function, measured TT concentrations might help to detect high-risk individuals for potential therapeutic interventions and to improve mortality risk assessment and outcome.

Tools such as genome resequencing and genome-wide association studies have recently been used to uncover a number of variants that affect drug toxicity and efficacy, as well as potential drug targets. But how much closer are we to incorporating pharmacogenomics into routine clinical practice? Five experts discuss how far we have come, and highlight the technological, informatics, educational and practical obstacles that stand in the way of realizing genome-driven medicine.