Cyanovirin-N Binding to N-Acetyl-d-glucosamine Requires Carbohydrate-Binding Sites on Two Different Protomers.

Cyanovirin-N (CV-N) binds high-mannose oligosaccharides on enveloped viruses with two carbohydrate-binding sites, one bearing high affinity and one low affinity to Manα(1-2)Man moieties. A tandem repeat of two CV-N molecules (CVN2) was tested for antiviral activity against human immunodeficiency virus type I (HIV-1) by using a domain-swapped dimer. CV-N was shown to bind N-acetylmannosamine (ManNAc) and N-acetyl-d-glucosamine (GlcNAc) when the carbohydrate-binding sites in CV-N were free to interact with these monosaccharides independently. CVN2 recognized ManNAc at a Kd of 1.4 µM and bound this sugar in solution, regardless of the lectin making amino acid side chain contacts on the targeted viral glycoproteins. An interdomain cross-contacting residue Glu41, which has been shown to be hydrogen bonding with dimannose, was substituted in the monomeric CV-N. The amide derivative of glucose, GlcNAc, achieved similar high affinity to the new variant CVN-E41T as high-mannose N-glycans, but binding to CVN2 in the nanomolar range with four binding sites involved or binding to the monomeric CVN-E41A. A stable dimer was engineered and expressed from the alanine-to-threonine-substituted monomer to confirm binding to GlcNAc. In summary, low-affinity binding was achieved by CVN2 to dimannosylated peptide or GlcNAc with two carbohydrate-binding sites of differing affinities, mimicking biological interactions with the respective N-linked glycans of interest and cross-linking of carbohydrates on human T cells for lymphocyte activation.

Bi-directionalized promoter systems allow methanol-free production of hard-to-express peroxygenases with Komagataella Phaffii.

BACKGROUND: Heme-incorporating peroxygenases are responsible for electron transport in a multitude of organisms. Yet their application in biocatalysis is hindered due to their challenging recombinant production. Previous studies suggest Komagataella phaffi to be a suitable production host for heme-containing enzymes. In addition, co-expression of helper proteins has been shown to aid protein folding in yeast. In order to facilitate recombinant protein expression for an unspecific peroxygenase (AnoUPO), we aimed to apply a bi-directionalized expression strategy with Komagataella phaffii. RESULTS: In initial screenings, co-expression of protein disulfide isomerase was found to aid the correct folding of the expressed unspecific peroxygenase in K. phaffi. A multitude of different bi-directionalized promoter combinations was screened. The clone with the most promising promoter combination was scaled up to bioreactor cultivations and compared to a mono-directional construct (expressing only the peroxygenase). The strains were screened for the target enzyme productivity in a dynamic matter, investigating both derepression and mixed feeding (methanol-glycerol) for induction. Set-points from bioreactor screenings, resulting in the highest peroxygenase productivity, for derepressed and methanol-based induction were chosen to conduct dedicated peroxygenase production runs and were analyzed with RT-qPCR. Results demonstrated that methanol-free cultivation is superior over mixed feeding in regard to cell-specific enzyme productivity. RT-qPCR analysis confirmed that mixed feeding resulted in high stress for the host cells, impeding high productivity. Moreover, the bi-directionalized construct resulted in a much higher specific enzymatic activity over the mono-directional expression system. CONCLUSIONS: In this study, we demonstrate a methanol-free bioreactor production strategy for an unspecific peroxygenase, yet not shown in literature. Hence, bi-directionalized assisted protein expression in K. phaffii, cultivated under derepressed conditions, is indicated to be an effective production strategy for heme-containing oxidoreductases. This very production strategy might be opening up further opportunities for biocatalysis.

Turpentine Ointment for the Treatment of Folliculitis: An Open, Prospective, Randomized, Placebo- and Comparator-Controlled Multicenter Trial.

INTRODUCTION: Folliculitis is a painful infection and inflammation of the hair follicles, mostly caused by bacterial, fungal, or, more rarely, viral infections. Turpentine derivatives have been used traditionally to treat various skin infections and could thus also be effective in treating folliculitis. We carried out an open, prospective, randomized, placebo- and comparator-controlled multicenter trial to evaluate the efficacy and safety of an ointment containing pine turpentine oil, larch turpentine, and eucalyptus oil in the treatment of acute folliculitis. METHODS: Seventy outpatients with acute folliculitis were treated with the turpentine ointment, a comparator (povidone iodine solution), or a placebo (Vaseline) for 7 days. Photographs of the affected skin areas were taken by the physicians at four visits and by the patients on a daily basis. Photographs were evaluated by blinded observers. Primary efficacy endpoint was the change in total hair follicle lesion counts. Secondary endpoints included the evolution of the lesion counts in the course of the study, responder rate (improvement of follicle lesions by at least one count), and the patient's global assessment. Safety endpoints were the tolerability of the treatments and adverse event recording. RESULTS: A decrease of follicle lesions counts was detected for both active treatments but not for placebo, but the differences among groups were not statistically significant. As for the secondary endpoints, the ointment showed statistically significant superiority over placebo for the evolution of the lesions during the course of the study (p = 0.017), the responder rate (p = 0.032), and the subjective efficacy assessment by patients (p = 0.029). All treatments were equally well tolerated, with a similar number of treatment-emergent adverse events. CONCLUSION: The turpentine ointment is an effective and safe option for the treatment of folliculitis.

Coherent Spin Preparation of Indium Donor Qubits in Single ZnO Nanowires.

Shallow donors in ZnO are promising candidates for photon-mediated quantum technologies. Utilizing the indium donor, we show that favorable donor-bound exciton optical and electron spin properties are retained in isolated ZnO nanowires. The inhomogeneous optical line width of single nanowires (60 GHz) is within a factor of 2 of bulk single-crystalline ZnO. Spin initialization via optical pumping is demonstrated and coherent population trapping is observed. The two-photon absorption width approaches the theoretical limit expected due to the hyperfine interaction between the indium nuclear spin and the donor-bound electron.

Immediate impact of child maltreatment on mental, developmental, and physical health trajectories.

OBJECTIVE: The immediate impact of child maltreatment on health and developmental trajectories over time is unknown. Longitudinal studies starting in the direct aftermath of exposure with repeated follow-up are needed. METHOD: We assessed health and developmental outcomes in 6-month intervals over 2 years in 173 children, aged 3-5 years at study entry, including 86 children with exposure to emotional and physical abuse or neglect within 6 months and 87 nonmaltreated children. Assessments included clinician-administered, self- and parent-report measures of psychiatric and behavioral symptoms, development, and physical health. Linear mixed models and latent growth curve analyses were used to contrast trajectories between groups and to investigate the impact of maltreatment features on trajectories. RESULTS: Maltreated children exhibited greater numbers of psychiatric diagnoses (b = 1.998, p < .001), externalizing (b = 13.29, p < .001) and internalizing (b = 11.70, p < .001) symptoms, impairments in cognitive (b = -11.586, p < .001), verbal (b = -10.687, p < .001), and motor development (b = -7.904, p = .006), and greater numbers of medical symptoms (b = 1.021, p < .001) compared to nonmaltreated children across all time-points. Lifetime maltreatment severity and/or age at earliest maltreatment exposure predicted adverse outcomes over time. CONCLUSION: The profound, immediate, and stable impact of maltreatment on health and developmental trajectories supports a biological embedding model and provides foundation to scrutinize the precise underlying mechanisms. Such knowledge will enable the development of early risk markers and mechanism-driven interventions that mitigate adverse trajectories in maltreated children.

Digestive enzyme expression in the large intestine of children with short bowel syndrome in a late stage of adaptation.

BACKGROUND AND AIMS: Intestinal adaptation in short bowel syndrome (SBS) includes morphologic processes and functional mechanisms. This study investigated whether digestive enzyme expression in the duodenum and colon is upregulated in SBS patients. METHOD: Sucrase-isomaltase (SI), lactase-phlorizin hydrolase (LPH), and neutral Aminopeptidase N (ApN) were analyzed in duodenal and colonic biopsies from nine SBS patients in a late stage of adaptation as well as healthy and disease controls by immunoelectron microscopy (IEM), Western blots, and enzyme activities. Furthermore, proliferation rates and intestinal microbiota were analyzed in the mucosal specimen. RESULTS: We found significantly increased amounts of SI, LPH, and ApN in colonocytes in most SBS patients with large variation and strongest effect for SI and ApN. Digestive enzyme expression was only partially elevated in duodenal enterocytes due to a low proliferation level measured by Ki-67 staining. Microbiome analysis revealed high amounts of Lactobacillus resp. low amounts of Proteobacteria in SBS patients with preservation of colon and ileocecal valve. Colonic expression was associated with a better clinical course in single cases. CONCLUSION: In SBS patients disaccharidases and peptidases can be upregulated in the colon. Stimulation of this colonic intestinalization process by drugs, nutrients, and pre- or probiotics might offer better therapeutic approaches.

Effect of allyl-isothiocyanate on survival and antimicrobial peptide expression following oral bacterial infections in Drosophila melanogaster.

Since infections with antibiotic-resistant bacteria cause increasing problems worldwide, the identification of alternative therapies is of great importance. Plant-derived bioactives, including allyl-isothiocyanate (AITC), have received attention for their antimicrobial properties. The present study therefore investigates the impact of AITC on survival and antimicrobial peptide (AMP) levels in Drosophila melanogaster challenged with the fly pathogenic bacteria Pectobacterium carotovorum subsp. carotovorum and Leuconostoc pseudomesenteroides. AITC, a sulfur-containing compound derived from glucosinolates, exhibits antimicrobial properties and has been suggested to modulate AMP expression. By using D. melanogaster, we demonstrate that AITC treatment resulted in a concentration-dependent decrease of survival rates among female flies, particularly in the presence of the Gram-negative bacterium Pectobacterium carotovorum subsp. carotovorum, whereas AITC did not affect survival in male flies. Despite the ability of isothiocyanates to induce AMP expression in cell culture, we did not detect significant changes in AMP mRNA levels in infected flies exposed to AITC. Our findings suggest sex-specific differences in response to AITC treatment and bacterial infections, underlining the complexity of host-pathogen interactions and potential limitations of AITC as a preventive or therapeutic compound at least in D. melanogaster models of bacterial infections.

Turpentine Ointment in Bacterial Skin Infections: A Randomized, Placebo-Controlled, Double-Blind Clinical Trial.

BACKGROUND: Turpentine-containing substances are considered effective in treating cutaneous bacterial infections, but reliable clinical data are scant. OBJECTIVE: We investigated the efficacy and safety of an ointment containing larch turpentine (from Larix decidua), eucalyptus oil (from Eucalyptus globulus), and turpentine oil (from Pinus pinaster) in outpatients with painful skin abscesses in a randomized, placebo-controlled, double-blind study. INTERVENTION: 116 outpatients with skin abscesses used verum or placebo for 10 days. Sum score of the patient's discomforts, changes in abscess size, rate of therapeutic success, and complete healing served as outcome parameters. RESULTS: Fifty-four patients were treated with verum and 56 with placebo. According to the patient's discomfort sum score, patients in the verum group showed a better improvement compared to the placebo group (7.3 vs. 4.7; p = 0.024), and subjective assessment by the investigators revealed a higher treatment success rate after verum (70% vs. 48%; p = 0.021). Complete healing was documented in 67% of the patients receiving verum versus 46% in the placebo group (p = 0.037). There was a positive trend toward a larger decrease in the abscess sizes in the verum group compared to the placebo group (p = 0.07). CONCLUSION: The ointment studied is an effective and safe option for the treatment of bacterial skin diseases.

Evaluation of reference genes for transcript analyses in Komagataella phaffii (Pichia pastoris).

BACKGROUND: The yeast Komagataella phaffii (Pichia pastoris) is routinely used for heterologous protein expression and is suggested as a model organism for yeast. Despite its importance and application potential, no reference gene for transcript analysis via RT-qPCR assays has been evaluated to date. In this study, we searched publicly available RNASeq data for stably expressed genes to find potential reference genes for relative transcript analysis by RT-qPCR in K. phaffii. To evaluate the applicability of these genes, we used a diverse set of samples from three different strains and a broad range of cultivation conditions. The transcript levels of 9 genes were measured and compared using commonly applied bioinformatic tools. RESULTS: We could demonstrate that the often-used reference gene ACT1 is not very stably expressed and could identify two genes with outstandingly low transcript level fluctuations. Consequently, we suggest the two genes, RSC1, and TAF10 to be simultaneously used as reference genes in transcript analyses by RT-qPCR in K. phaffii in future RT-qPCR assays. CONCLUSION: The usage of ACT1 as a reference gene in RT-qPCR analysis might lead to distorted results due to the instability of its transcript levels. In this study, we evaluated the transcript levels of several genes and found RSC1 and TAF10 to be extremely stable. Using these genes holds the promise for reliable RT-qPCR results.

Dose-Dependent Effects of the Cimicifuga racemosa Extract Ze 450 in the Treatment of Climacteric Complaints: A Randomized, Placebo-Controlled Study.

Extracts from Cimicifuga racemosa (CR, synonym Actaea racemosa) have shown efficacy in trials in women with menopausal symptoms. Yet, dose dependency remains unclear. Therefore, 180 female outpatients with climacteric complaints were treated for 12 weeks in a randomized, double-blind, placebo-controlled, 3-armed trial (CR extract Ze 450 in 6.5 mg or 13.0 mg, or placebo). Primary outcome was the difference in menopausal symptoms (vasomotor, psychological, and somatic), assessed by the Kupperman Menopausal Index between baseline and week 12. Secondary efficacy variables were patients' self-assessments of general quality of life (QoL), responder rates, and safety. Compared to placebo, patients receiving Ze 450 showed a significant reduction in the severity of menopausal symptoms in a dose-dependent manner from baseline to endpoint (mean absolute differences 17.0 (95% CI 14.65-19.35) score points, P < 0.0001 for 13.0 mg; mean absolute differences 8.47 (95% CI 5.55-11.39) score points, P = 0.0003 for 6.5 mg). QoL and responder rates corresponded with the main endpoint. Changes in menopausal symptoms and QoL were inversely correlated. Reported adverse events and clinical laboratory testing did not raise safety concerns. The CR extract Ze 450 is an effective and well-tolerated nonhormonal alternative to hormone treatment for symptom relief in menopausal women.

Petasol butenoate complex (Ze 339) relieves allergic rhinitis-induced nasal obstruction more effectively than desloratadine.

BACKGROUND: Allergic rhinitis symptoms of itching, sneezing, rhinorrhea, and nasal obstruction significantly decrease patients' quality of life. Compared with histamine and leukotriene receptor antagonists, the petasol butenoate complex Ze 339 displays pharmacologically distinct properties. In vitro it inhibits the biosynthesis of leukotrienes and mediator release from activated eosinophils. OBJECTIVE: This study aimed to assess the efficacy and mode of action of Ze 339, desloratadine, and placebo on allergic rhinitis symptoms, nasal airflow, and local mediator levels after unilateral nasal allergen provocation. METHODS: In this double-blind, randomized, crossover study 18 subjects with allergic rhinitis to grass pollen received Ze 339, desloratadine, and placebo for 5 days before nasal allergen challenge with grass pollen extract. Rhinomanometry, symptom assessment, and local inflammatory mediator measurement were performed during the 24 hours after allergen challenge. RESULTS: With Ze 339, the patient's time to recovery (5.4 ± 1.6 hours) from nasal obstruction after allergen challenge (time for return to 90% of baseline value ± SEM) was significantly shorter than with placebo (9.1 ± 2.3 hours, P = .035) and desloratadine (10.7 ± 2.5 hours, P = .022). Likewise, Ze 339's standardized symptom assessment for nasal obstruction (3.2 ± 1.3 hours) showed significantly faster relief (time for return to baseline value ± SEM compared with placebo, 8.3 ± 2.4 hours; P = .027) and desloratadine (4.5 ± 1.2 hours, P = .030). One interesting finding was that Ze 339 significantly reduced IL-8 and leukotriene B(4) levels in nasal secretions before challenge. CONCLUSION: When compared with desloratadine and placebo, Ze 339 shows better efficacy in relieving nasal obstruction symptoms and inhibiting critical components of the chemokine network and as such represents a novel symptomatic and possible prophylactic treatment for allergic rhinitis.

3D pose estimation enables virtual head fixation in freely moving rats.

The impact of spontaneous movements on neuronal activity has created the need to quantify behavior. We present a versatile framework to directly capture the 3D motion of freely definable body points in a marker-free manner with high precision and reliability. Combining the tracking with neural recordings revealed multiplexing of information in the motor cortex neurons of freely moving rats. By integrating multiple behavioral variables into a model of the neural response, we derived a virtual head fixation for which the influence of specific body movements was removed. This strategy enabled us to analyze the behavior of interest (e.g., front paw movements). Thus, we unveiled an unexpectedly large fraction of neurons in the motor cortex with tuning to the paw movements, which was previously masked by body posture tuning. Once established, our framework can be efficiently applied to large datasets while minimizing the experimental workload caused by animal training and manual labeling.

Fast and efficient CRISPR-mediated genome editing in Aureobasidium using Cas9 ribonucleoproteins.

Species of the genus Aureobasidium are ubiquitous, polyextremotolerant, "yeast-like" ascomycetes used for the industrial production of pullulan and other products and as biocontrol agents in agriculture. Their application potential and wide-spread occurrence make Aureobasidium spp. interesting study objects. The availability of a fast and efficient genome editing method is an obvious advantage for future basic and applied research on Aureobasidium. In this study, we describe the development of a CRISPR/Cas9-based genome editing method using ribonucleoproteins (RNPs) in A. pullulans and A. melanogenum. We demonstrate that this method can be used for single and multiplex genome editing using only RNPs by targeting URA3 (encoding for orotidine-5'-phosphate decarboxylase), ADE2 (encoding for phosphoribosylaminoimidazole carboxylase) and ARG4 (encoding for argininosuccinate lyase). We demonstrate the applicability of Trichoderma reesei pyr4 and Aspergillus fumigatus pyrG to complement the URA3 deficiency. Further, we show that using RNPs improves the homologous recombination rate and 20 bp long homologous flanks are sufficient. Therefore, the repair cassettes can be constructed by a single PCR, abolishing the need for laborious and time-consuming cloning, which is necessary for previously described methods for CRISPR-mediated genome editing in these fungi. The here presented method allows fast and efficient genome editing for gene deletions, modifications, and insertions in Auresobasidium with a minimized risk of off-target effects.

FunOrder 2.0 - a method for the fully automated curation of co-evolved genes in fungal biosynthetic gene clusters.

Coevolution is an important biological process that shapes interacting proteins - may it be physically interacting proteins or consecutive enzymes in a metabolic pathway, such as the biosynthetic pathways for secondary metabolites. Previously, we developed FunOrder, a semi-automated method for the detection of co-evolved genes, and demonstrated that FunOrder can be used to identify essential genes in biosynthetic gene clusters from different ascomycetes. A major drawback of this original method was the need for a manual assessment, which may create a user bias and prevents a high-throughput application. Here we present a fully automated version of this method termed FunOrder 2.0. In the improved version, we use several mathematical indices to determine the optimal number of clusters in the FunOrder output, and a subsequent k-means clustering based on the first three principal components of a principal component analysis of the FunOrder output to automatically detect co-evolved genes. Further, we replaced the BLAST tool with the DIAMOND tool as a prerequisite for using larger proteome databases. Potentially, FunOrder 2.0 may be used for the assessment of complete genomes, which has not been attempted yet. However, the introduced changes slightly decreased the sensitivity of this method, which is outweighed by enhanced overall speed and specificity.

Neoadjuvant radiochemotherapy and surgery for advanced rectal cancer : prognostic significance of tumor regression.

PURPOSE: Preoperative radiochemotherapy is widely used in the treatment of locally advanced rectal cancer. The predictive value of response to neoadjuvant treatment remains uncertain. We retrospectively evaluated the impact of downstaging and tumor regression as prognostic factors and its influence on the ability to perform sphincter-sparing surgery. PATIENTS AND METHODS: A total of 72 consecutive patients with advanced rectal cancer were included in this retrospective analysis. All patients were treated with preoperative 5-fluorouracil-based chemotherapy and pelvic radiation with a total dose of 50.4 Gy followed by surgery 6 weeks later. RESULTS: A sphincter-preserving procedure could be performed on 42 patients, and in all 72 patients complete resection (R0) was achieved. A pathological complete response (ypT0, ypN0) was achieved in 8 (11%) patients. None of the patients showing a complete pathological response relapsed or died during the follow-up period. At a median follow-up of 28 months, 65 patients were alive, none of these patients had local recurrence and 15 patients had metastatic disease. Patients showing a complete pathological response had a significantly better 2-year disease-free survival compared to patients with ≥10% residual tumor cells (p = 0.024). Patients < 65 years showed a significantly better response rate, compared with those > 65 years of age (p = 0.036). Acute toxicity was moderate. CONCLUSION: Preoperative radiochemotherapy is an effective and safe treatment for patients with locally advanced rectal cancer. Pathological parameters after preoperative radiochemotherapy, including tumor regression grading, could be correlated with disease-free survival. The impact of tumor regression grading needs to be further validated in prospective clinical trials.

Impact of Food-Derived Bioactive Compounds on Intestinal Immunity.

The gastrointestinal system is responsible for the digestion and the absorption of nutrients. At the same time, it is essentially involved in the maintenance of immune homeostasis. The strongest antigen contact in an organism takes place in the digestive system showing the importance of a host to develop mechanisms allowing to discriminate between harmful and harmless antigens. An efficient intestinal barrier and the presence of a large and complex part of the immune system in the gut support the host to implement this task. The continuous ingestion of harmless antigens via the diet requires an efficient immune response to reliably identify them as safe. However, in some cases the immune system accidentally identifies harmless antigens as dangerous leading to various diseases such as celiac disease, inflammatory bowel diseases and allergies. It has been shown that the intestinal immune function can be affected by bioactive compounds derived from the diet. The present review provides an overview on the mucosal immune reactions in the gut and how bioactive food ingredients including secondary plant metabolites and probiotics mediate its health promoting effects with regard to the intestinal immune homeostasis.

On the permittivity of titanium dioxide.

Conductive rutile TiO2 has received considerable attention recently due to multiple applications. However, the permittivity in conductive, reduced or doped TiO2 appears to cause controversy with reported values in the range 100-10,000. In this work, we propose a method for measurements of the permittivity in conductive, n-type TiO2 that involves: (i) hydrogen ion-implantation to form a donor concentration peak at a known depth, and (ii) capacitance-voltage measurements for donor profiling. We cannot confirm the claims stating an extremely high permittivity of single crystalline TiO2. On the contrary, the permittivity of conductive, reduced single crystalline TiO2 is similar to that of insulating TiO2 established previously, with a Curie-Weiss type temperature dependence and the values in the range 160-240 along with the c-axis.

Species-dependent transport and modulation properties of human and mouse multidrug resistance protein 2 (MRP2/Mrp2, ABCC2/Abcc2).

Multidrug resistance protein 2 (MRP2/Mrp2) is a transporter that can influence the absorption, distribution, and elimination of many drugs. Mrp2 knockout mice are being used to study Mrp2 functions in vivo, including pharmacokinetics of drugs. To assess possible species-specific differences between human MRP2 and mouse Mrp2, we generated polarized cell lines expressing mouse Mrp2 and used these to investigate transport of clinically important agents. We also tested the ability of other drugs to modulate MRP2/Mrp2-mediated transport, a phenomenon that can lead to drug-drug interactions. In MDCK cells stably expressing human MRP2 or mouse Mrp2, saquinavir and docetaxel were more efficiently transported by mouse Mrp2, whereas vinblastine was transported better by human MRP2. MRP2/Mrp2-mediated transepithelial transport of several drugs could be stimulated by probenecid and sulfanitran, but stimulation was often more pronounced for human MRP2 than for mouse Mrp2. Interestingly, for some drugs the MRP2 modulator sulfinpyrazone had opposite effects on both transporters, stimulating human MRP2 and inhibiting mouse Mrp2 activity. In vesicular transport studies, transport of estradiol-17beta-glucuronide by mouse Mrp2 showed homotropic cooperativity, as previously described for human MRP2. The MRP2 modulators again showed differential effects on estradiol-17beta-glucuronide transport, most notably with sulfinpyrazone stimulating human MRP2 and profoundly inhibiting mouse Mrp2 activity. In conclusion, although human and mouse MRP2/Mrp2 have largely overlapping substrate specificities, there are important species differences in the transport efficiency of MRP2 substrates and in the modulation of transport by other compounds. These differences should be taken into account when results obtained in mice are extrapolated to humans.

Breast cancer resistance protein and P-glycoprotein expression in patients with newly diagnosed and therapy-refractory ulcerative colitis compared with healthy controls.

AIMS: Efflux transporters such as breast cancer resistance protein (BCRP/ABCG2) and P-glycoprotein (Pgp; MDR1/ABCB1) are protecting the enterocytes from potentially toxic compounds. Both transporters have been reported to be downregulated in patients with active ulcerative colitis (UC). The aim of this study was to evaluate transporter expression in both unaffected and inflamed mucosa of patients with active UC, in drug-naïve and treated patients with UC and compare the results with transporter expression in healthy subjects. METHODS: Transporter expression was determined with real-time RT-PCR (TaqMan) in inflamed and unaffected mucosa of newly diagnosed (n = 12) and therapy-refractory (n = 11) patients with UC. Expression levels were compared with UC patients in remission (n = 11) and control subjects (n = 26). BCRP and Pgp expression was evaluated by immunohistochemistry. RESULTS: Compared with unaffected mucosa, BCRP expression was significantly reduced in inflamed mucosa of newly diagnosed drug-naïve patients with UC (expression reduced to 30%) as well as in patients not responding to treatment (reduced to 25%) with either 5-aminosalicylates (n = 7) or prednisone (n = 4). Unaffected mucosa of UC patients showed comparable transporter expression to unaffected mucosa of control subjects. MDR1 expression depicts a similar pattern. Protein staining for Pgp and BCRP was significantly reduced in the inflamed mucosa of patients with active UC. CONCLUSIONS: Expression of both efflux transporters BCRP and MDR1 is reduced, but only in inflamed tissue of patients with active UC. Transporter expression in unaffected mucosa of patients with active UC is comparable to healthy controls. The data suggest that the inflammatory process is responsible for the reduced levels. A major role in the pathogenesis of UC is unlikely.