http://repub.eur.nl/res/org/9813/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/26498/ 2011-09-21T00:00:00Z The history of sarcoidosis begins in 1899 when the Norwegian dermatologist Ceasar Boeck described nodular skin lesions characterized by epitheloid cells and a few giant cells as multiple benign sarcoid of the skin. Now, many years later, a lot more is known about sarcoidosis. The definition of sarcoidosis is described in the American Thoracic Society statement on sarcoidosis in 1999: sarcoidosis is regarded as a multisystem disorder of unknown cause, commonly affecting young and middle aged adults, with bilateral hilar adenopathy, pulmonary infiltrates, eye and skin lesions. Also other organs like the liver, the spleen, lymph nodes, salivary glands, the heart, muscles, bones and the nervous system can be involved. The diagnosis is established when clinical and radiological findings are supported by histological evidence of non-caseating epitheloid cell granulomas. Granulomas caused by other diseases need to be excluded. Sarcoidosis affects people of all racial and ethnic groups and occurs at all ages although it usually develops before the age of 50 years, with a peak incidence at 20-39 years. The incidence of sarcoidosis varies widely all over the world with the highest incidence in the northern European countries. There is a predispondance of sarcoidosis in females. In America, the incidence of sarcoidosis in Afro-Americans is roughly three times higher compared to white americans. In black Americans the peak incidence occurs later in live and sarcoidosis is more often chronic and fatal. Berge, B. ten http://repub.eur.nl/res/pub/26686/ 2011-07-01T00:00:00Z The long-term effects of lung cancer computed tomography (CT) screening on health-related quality of life (HRQoL) have not yet been investigated. In the Dutch-Belgian Randomised Lung Cancer Screening Trial (NELSON trial), 1,466 participants received questionnaires before randomisation (T0), 2 months after baseline screening (screen group only; T1) and at 2-yr follow-up (T2). HRQoL was measured as generic HRQoL (12-item short-form questionnaire and EuroQoL questionnaire), anxiety (Spielberger State-Trait Anxiety Inventory) and lung cancer-specific distress (impact of event scale (IES)). Repeated measures of ANOVA were used to analyse differences between the screen and control groups, and between indeterminate (requiring a follow-up CT) and negative screening result groups. At T0 and T2 there were no significant differences in HRQoL scores over time between the screen and control groups, or between the indeterminate or negative second-round screening result group. There was a temporary increase in IES scores after an indeterminate baseline result (T0: mean 4.0 (95% CI 2.8-5.3); T1: mean 7.8 (95% CI 6.5-9.0); T2: mean 4.5 (95% CI 3.3-5.8)). At 2-yr follow-up, the HRQoL of screened subjects was similar to that of control subjects, the unfavourable short-term effects of an indeterminate baseline screening result had resolved and an indeterminate result at the second screening round had no impact on HRQoL. Copyright Bergh, K.A.M. van den Essink-Bot, M.L.E. Borsboom, G.J.J.M. Scholten, E.T. Klaveren, R.J. van Koning, H.J. de http://repub.eur.nl/res/pub/26153/ 2011-06-01T00:00:00Z Receiving a lung cancer computed tomography screening result might be a teachable moment for smoking cessation, but it might also unintentionally reassure smokers to continue smoking. The objective of the present study was to investigate whether test results were associated with smoking abstinence in the Dutch-Belgian Randomised Controlled Lung Cancer Screening Trial (NELSON trial). Two random samples of male smokers who had received either only negative test results (n=550) or one or more indeterminate test result (n=440) were sent a questionnaire 2 yrs after randomisation. Smokers with an indeterminate result reported more quit attempts (p=0.02), but the prolonged abstinence rate in smokers receiving a negative test (46 (8.9%) out of 519 subjects) was comparable with the abstinence rate in smokers with one or more indeterminate results (48 (11.5%) out of 419 subjects) (p=0.19). A statistically insignificant increase was found after one or more indeterminate test result (10.9 and 15.0%, respectively) compared with receiving only negative test results (8.9%) (p=0.26). In conclusion, the outcome of the screening test had no impact on future smoking abstinence in male smokers, although all results suggest more favourable implications after one or more follow-up recommendations. Screening test outcomes could be used as a teachable moment for smoking cessation. Copyright Aalst, C.M. van der Klaveren, R.J. van Bergh, K.A.M. van den Willemsen, M.C. Koning, H.J. de http://repub.eur.nl/res/pub/26617/ 2011-06-01T00:00:00Z Background: A new analytical MS method using isotope dilution combined with MALDI-triple quadrupole MS/MS has been developed and validated for the determination of methotrexate and 7-hydroxymethotrexate in plasma. Methotrexate, methotrexate-d3, 7-hydroxymethotrexate and 7-hydroxymethotrexate-d3 were monitored by selected reaction monitoring using the transitions m/z 455.2→308.2, 458.2→311.2, 471.2→324.2 and 474.2→327.2 for methotrexate, methotrexate-d3, 7-hydroxymethotrexate and 7-hydroxymethotrexate- d3, respectively. Results: The LLOQ was 1 nmol/l for methotrexate and 7-hydroxymethotrexate while the limit of detection was 0.3 nmol/l for both analytes. The new developed method was cross-validated by a fluorescence polarization immunoassay and tested for its clinical feasibility by measuring plasma samples from patients suffering from acute lymphoblastic leukemia. Plasma methotrexate concentrations ranged between 66.0 and 954 nmol/l and observed 7-hydroxymethotrexate/methotrexate ratios ranged between 0.1 and 32.4, respectively. Conclusion: The new method showed comparable analytical performances as the fluorescence polarization immunoassay, but analyte specificity and sensitivity of the newly developed method were significantly better. Meesters, R.J.W. Boer, E. den Mathot, R.A.A. Jonge, R. de Klaveren, R.J. van Lindemans, J. Luider, T.M. http://repub.eur.nl/res/pub/25527/ 2011-05-01T00:00:00Z Imiquimod has been shown to be an effective treatment for usual type vulvar intraepithelial neoplasia (uVIN). Since local inflammation and burning are common side effects, patients often use nonsteroidal anti-inflammatory drugs (NSAIDs). Our study investigated whether NSAID-use, which has been documented to inhibit the cell-mediated immune response, interferes with the outcome of imiquimod treatment. Monocyte-derived dendritic cells (moDCs) and Langerhans cells (moLCs) were cultured in the presence of NSAIDs. The expression of relevant surface markers (CD80, CD86, CD40, HLA-DR, CCR6 and CCR7), stimulatory function, and cytokine production were evaluated. Furthermore, we analyzed in uVIN patients whether frequent NSAID-use had an effect on the clinical response and on immunocompetent cell counts before and after imiquimod treatment. Although an effect was observed on the expression of moDC and moLC maturation markers, NSAIDs did not affect the ability of moDCs and moLCs to stimulate allogeneic T-cell proliferation, or the production of cytokines in an allogeneic T-cell stimulation assay. In agreement with this, in uVIN patients treated with imiquimod, no interference of frequent NSAID-use with clinical outcome was observed. However, we did notice that high CD1a+and CD207+cell counts in frequent NSAID-users before treatment seemed to predict a favourable response to imiquimod treatment. Our data indicate that NSAID-use does not seem to interfere with moDC and moLC function and does not interfere with immunomodulatory properties of imiquimod in uVIN patients. Therefore, NSAIDs can safely be used to reduce imiquimod side effects in uVIN patients during treatment. Copyright Terlou, A. Kleinjan, A. Beckmann, I. Heijmans-Antonissen, C. Seters, M. van Santegoets, L.A.M. Beurden, M. van Helmerhorst, T.J.M. Blok, L.J. http://repub.eur.nl/res/pub/26473/ 2011-04-22T00:00:00Z Although deposition of uric acid (UA) crystals is known as the cause of gout, it is unclear whether UA plays a role in other inflammatory diseases. We here have shown that UA is released in the airways of allergen-challenged asthmatic patients and mice, where it was necessary for mounting T helper 2 (Th2) cell immunity, airway eosinophilia, and bronchial hyperreactivity to inhaled harmless proteins and clinically relevant house dust mite allergen. Conversely, administration of UA crystals together with protein antigen was sufficient to promote Th2 cell immunity and features of asthma. The adjuvant effects of UA did not require the inflammasome (Nlrp3, Pycard) or the interleukin-1 (Myd88, IL-1r) axis. UA crystals promoted Th2 cell immunity by activating dendritic cells through spleen tyrosine kinase and PI3-kinase δ signaling. These findings provide further molecular insight into Th2 cell development and identify UA as an essential initiator and amplifier of allergic inflammation. Kool, M. Willart, M.A. Lambrecht, B.N.M. Nimwegen, M. van Bergen, I.M. Pouliot, P. Virchow, J.C. Rogers, N. Osorio, F. Reis e Sousa, C. Hammad, H. http://repub.eur.nl/res/pub/25552/ 2011-04-01T00:00:00Z Chronic inflammatory T-cell-mediated diseases such as inflammatory bowel disease (IBD) are often treated with immunosuppressants including corticosteroids. In addition to the intended T-cell suppression, these farmacons give rise to many side effects. Recently, immunosuppressive phospholipids have been proposed as less-toxic alternatives. We aimed to investigate the immunoregulatory capacities of the naturally occurring phospholipid phosphatidylinositol (PI). Systemic PI treatment dramatically reduced disease severity and intestinal inflammation in murine 2,4,6-trinitrobenzene sulfonic acid (TNBS) colitis. Moreover, PI treatment inhibited the inflammatory T-cell response in these mice, as T cells derived from colon-draining LN of PI-treated mice secreted less IL-17 and IFN-γ upon polyclonal restimulation when compared to those of saline-treated mice. Further characterization of the suppressive capacity of PI revealed that the phospholipid suppressed Th cell differentiation in vitro irrespective of their cytokine profile by inhibiting proliferation and IL-2 release. In particular, PI diminished IL-2 mRNA expression and inhibited ERK1-, ERK-2-, p38- and JNK-phosphorylation. Crucially, PI did not ablate Treg differentiation or the antigen-presenting capacity of DCs in vitro. These data validate PI as a pluripotent inhibitor that can be applied mucosally as well as systemically. Its compelling functions render PI a promising novel physiological immune suppressant. Dieren, J.M. van Simons-Oosterhuis, Y. Lambrecht, B.N.M. Samsom, J.N. Nieuwenhuis, E.E.S. Raatgeep, H.C.R. Lindenbergh-Kortleve, D.J. Lambers, M.E.H. Woude, C.J. van der Kuipers, E.J. Snoek, G.T. Potman, R. Hammad, H. http://repub.eur.nl/res/pub/23055/ 2011-03-01T00:00:00Z Mulshine, J.L. Klaveren, R.J. van http://repub.eur.nl/res/pub/21745/ 2010-12-15T00:00:00Z Recently, we reported on the efficacy of imiquimod for treatment of usual type vulvar intraepithelial neoplasia (uVIN). A histologic regression of uVIN to normal tissue was observed in 58% of patients. As success of treatment is related to clearance of high-risk human papilloma virus (HPV), the aim of our study was to assess differences in immune cell counts and in the expression of p16INK4a in VIN tissue before and after imiquimod treatment, in relation to HPV clearance and clinical response. Vulvar tissue samples taken prior to imiquimod treatment and 4 weeks after treatment were tested for the presence of HPV. Previously determined immune cell counts (CD1a, CD207, CD208, CD123/CD11c, CD94, CD4, CD8 and CD25/HLA-DR) in epidermis and dermis of 25 VIN patients and 19 healthy controls were completed with the counts for CD14 and CD68. The expression of p16INK4a was investigated by immunohistochemistry in 15 patients. Before imiquimod treatment, both HPV cleared and HPV noncleared patients showed mainly in the dermis significantly upregulated immune cell counts compared to healthy controls. However, in patients that cleared HPV and showed histologic regression already 4 weeks after imiquimod treatment, immune cell counts and p16INK4a expression were normalized. In conclusion, our data indicate that imiquimod-induced clearance of HPV results in normalization of counts for certain immune cells and is strongly correlated with histologic regression of the disease. Terlou, A. Seters, M. van Kleinjan, A. Heijmans-Antonissen, C. Santegoets, L.A.M. Beckmann, I. Beurden, M. van Helmerhorst, T.J.M. Blok, L.J. http://repub.eur.nl/res/pub/22286/ 2010-12-08T00:00:00Z Malignant mesothelioma (MM) is a highly aggressive neoplasm caused by neoplastic transformation of mesothelial cells that line the body’s serous cavities and the internal organs. In the majority of patients mesothelioma is localized within the pleural cavity. At this moment, no curative medical procedures are available. With median survival of 9 to 12 month after first signs of illness, the prognosis is poor. Mesothelioma is strongly associated with the exposure to airborne asbestos particles. Although the relation between exposure to asbestos and the occurrence of disease was already reported by the ancient Greek geographer Strabo and the roman naturist Gaius Plinius Secundus in 23 AD*, the first scientific report was published in the 1960’s by Wagner et al. He reported a strong correlation between exposure to asbestos and the occurrence of mesothelioma, among asbestos-mine-workers in South-African’s Cape Province. Studies of Stumphius et al. noticed an increased incidence in mesothelioma cases among shipyard-workers in the “Royal Schelde” shipyard. Even though it became more distinct that asbestos exposure was one of the main causes for mesothelioma, the commercial use of asbestos peaked during the seventies. Tons of asbestos-containing materials are still present in buildings, ships and infrastructures. Production and usage of asbestos-containing material maintained in the Netherlands till the interdiction of asbestos-use in 1993. As millions of people were exposed to carcinogenic fibres, with accompanying serious health risks undisputed there is a responsibility for governments to support mesothelioma research. The United Kingdom’s Ministry of Justice has recently announced that the U.K. government is obligated to address the medical aspects of mesothelioma. It is a misconception that with the ban of asbestos-use, the occurrence of mesothelioma will disappear within the following decades. Many people world wide are incidentally exposed to asbestos fibres. During the collapse of the New York World Trade Centre in 2001 the citizens of New York not only faced the tragedy of a terrorist attack, but as a consequence thousands of people were exposed to a dust-cloud containing 400 tons of asbestos fibres (4% of all fibres within the dust-cloud). Soon after 9/11 the Mesothelioma Applied Research Foundation (MARF) was established to fund research, investigating new treatment strategies to cure mesothelioma. Veltman, J.D. http://repub.eur.nl/res/pub/20292/ 2010-12-01T00:00:00Z Background: It is believed that making an informed decision about (screening) participation is associated with better health-related quality of life (HRQoL) outcomes. This is the first study in cancer screening to explore this association in subjects participating in a lung cancer computed tomography (CT) screening trial. Methods: Participants that made either an informed decision to participate (n = 155) or not (n = 133) were selected for this study. Differences in HRQoL, measured as generic HRQoL (Short Form 12 [SF-12] and EuroQol questionnaire [EQ-5D]), anxiety/distress (State-Trait Anxiety Inventory [STAI-6], Impact of Event Scale [IES] and Consequences of Screening-Lung Cancer [COS-LC]), were tested with Mann-Whitney U tests and ANOVA at three assessment points (when deciding about participation, before trial randomisation and 2 months after receiving the CT result). Results: Subjects who made an informed decision to participate had no better scores than those who did not make an informed decision for 23 out of 24 HRQoL comparisons, except for a better mean score for mental health (Mental Component Summary (MCS) = 53.9 ± 9.2 versus 51.0 ± 10.1, p = 0.003) before randomisation. For subjects with an indeterminate CT result (n = 64), no significant differences were found between subjects with (n = 35) or without (n = 29) an informed decision. Conclusion: Subjects who did not make an informed decision to participate in lung cancer CT screening trial did not experience worse HRQoL during screening than subjects who did make an informed decision, either in general or after receiving an indeterminate result. Bergh, K.A.M. van den Essink-Bot, M.L.E. Klaveren, R.J. van Koning, H.J. de http://repub.eur.nl/res/pub/21929/ 2010-12-01T00:00:00Z Within the group of Idiopathic Interstitial Pneumonias (IIPs), above all Idiopathic Pulmonary Fibrosis (IPF) poses a considerable diagnostic and therapeutic problem. Although genetic profiling indicates that IPF, Non Specific Interstitial Pneumonia (NSIP), and chronic hypersensitivity pneumonitis (HP) are distinctly different diseases, in every day practice these diseases can be difficult to tell apart. Furthermore, treatment of these diseases is notoriously difficult. Serum biomarkers reflect our understanding of the underlying pathogenesis and potentially fulfill a role in establishing a diagnosis, prognosis and therapy. While no single biomarker is currently able to accurately predict the presence or absence of an IIP, a composite of several markers holds promise for the future. Several biomarkers, such as KL-6, surfactant proteins and circulating fibrocytes, appear to contribute to our insight into disease progression and prognosis. It is however uncertain whether these markers give us additional information to common diagnostic tests and their value has as yet to be validated for every day practice. Fortunately, the potential of biomarkers is increasingly recognized and biomarker data are prospectively gathered in current placebo-controlled therapeutic trials. Blink, B. van den Wijsenbeek, M.S. Hoogsteden, H.C. http://repub.eur.nl/res/pub/28616/ 2010-12-01T00:00:00Z An analytical assay has been developed and validated for ultrafast and high-throughput mass spectrometric determination of pemetrexed concentrations in plasma using matrix assisted laser desorption/ionization-triple quadrupole-tandem mass spectrometry. Patient plasma samples spiked with the internal standard methotrexate were measured by multiple reaction monitoring. The detection limit was 0.4 fmol/μL, lower limit of quantification was 0.9 fmol/μL, and upper limit of quantification was 60 fmol/μL, respectively. Overall observed pemetrexed concentrations in patient samples ranged between 8.7 (1.4) and 142.7 (20.3)∈pmol/μL (SD). The newly developed mass spectrometric assay is applicable for (routine) therapeutic drug monitoring of pemetrexed concentrations in plasma from non-small cell lung cancer patients. Meesters, R.J.W. Cornelissen, R. Klaveren, R.J. van Jonge, R. de Boer, E. den Lindemans, J. Luider, T.M. http://repub.eur.nl/res/pub/21595/ 2010-11-01T00:00:00Z T lymphocytes depend on the thymic microenvironment for initiation of the T-cell developmental program. As the progenitors in the thymus have lost the capacity to self-renew, this process depends on the constant influx of hematopoietic progenitors that originate in the bone marrow. Nevertheless, thymic emigrants are heterogeneous and retain developmental plasticity for both the myeloid and lymphoid lineages. It is the role of the thymic microenvironment to steer these uncommitted progenitors toward a T-cell fate. Still, the thymus also generates a unique population of thymic NK cells, thus raising the question of how the T versus NK lymphoid cell fate is determined intrathymically. Many factors have been implicated in the developmental pathways in the thymus, and the processes are characterized by both subtle and not so subtle modifications in gene expression. In this review, we consider the crucial factors governing lineage determination of T cells versus NK cells from bi-potent thymic NK/T precursors. Recent reports have shed new light on the complex interactions of cytokines and transcription factors at different cell fate decision branch points in thymopoiesis. We discuss the implications of these findings and propose a model that may be applicable at this critical thymic NK/T juncture. Klein Wolterink, R.G.J. García-Ojeda, M.E. Vosshenrich, C.A. Hendriks, R.W. Santo, J.P. di http://repub.eur.nl/res/pub/21635/ 2010-10-29T00:00:00Z The adapter protein Slp65 and Bruton's tyrosine kinase (Btk) are key components of the precursor-B (pre-B) cell receptor (pre-BCR) signaling pathway. Slp65-deficient mice spontaneously develop pre-B-cell leukemia, expressing high levels of the pre-BCR on their cell surface. As leukemic Slp65-deficient pre-B cells express the recombination activating genes (Rag)1 and Rag2, and manifest ongoing immunoglobulin (Ig) light-chain rearrangement, it has been hypothesized that deregulated recombinase activity contributes to malignant transformation. In this report, we investigated whether Rag-induced DNA damage is involved in oncogenic transformation of Slp65-deficient B cells. We employed Btk/Slp65 double-deficient mice carrying an autoreactive 3-83μδ BCR transgene. When developing B cells in their bone marrow express this BCR, the V(D)J recombination machinery will be activated, allowing for secondary Ig light-chain gene rearrangements to occur. This phenomenon, called receptor editing, will rescue autoreactive B cells from apoptosis. We observed that 3-83μδ transgenic Btk/Slp65 double-deficient mice developed B-cell leukemias expressing both the 3-83μδ BCR and the pre-BCR components λ5/VpreB. Importantly, such leukemias were found at similar frequencies in mice concomitantly deficient for Rag1 or the non-homologous end-joining factor DNA-PKcs. We therefore conclude that malignant transformation of Btk/Slp65 double-deficient pre-B cells is independent of deregulated V(D)J recombination activity.Leukemia advance online publication, 29 October 2010; doi:10.1038/leu.2010.246. Ta, T.B.V. Haan, A.B. Bruijn, M.J.W. de Dingjan, G.M. Hendriks, R.W. http://repub.eur.nl/res/pub/27536/ 2010-10-01T00:00:00Z Allergen-specific immunotherapy (IT) uniquely renders long-term relief from allergic symptoms and is associated with elevated serum levels of allergen-specific IgG and IgA. The allergen-specific IgG response induced by IT treatment was shown to be critical for suppression of the immediate phase of the allergic response in mice, and this suppression was partially dependent on signaling through FcγRIIB. To investigate the relevance of the allergen-specific IgG responses for suppression of the Th2-driven late-phase allergic response, we performed IT in a mouse model of allergic asthma in the absence of FcγRIIB or FcγRI/FcγRIII signaling. We found that suppression of Th2 cell activity, allergic inflammation, and allergen-specific IgE responses is independent of FcγRIIB and FcγRI/FcγRIII signaling. Moreover, we show that the IT-induced allergen-specific systemic IgG or IgA responses and B cell function are dispensable for suppression of the late-phase allergic response by IT treatment. Finally, we found that the secretory mucosal IgA response also is not required for suppression of the Th2-driven allergic inflammation by IT. These data are in contrast to the suppression of the immediate phase of the allergic response, which is critically dependent on the induced allergenspecific serum IgG response. Hence, IT-induced suppression of the immediate and late phases of the allergic response is governed by divergent and independent mechanisms. Our data show that the IT-induced suppression of the Th2 cell-dependent late-phase allergic response is independent of the allergen-specific IgG and IgA responses that are associated with IT treatment. Copyright Shirinbak, S. Taher, Y.A. Nawijn, M.C. Maazi, H. Gras, R. Esch, B.C.A.M. van Henricks, P.A.J. Samsom, J.N. Verbeek, J.S. Lambrecht, B.N.M. Oosterhout, A.J.M. van http://repub.eur.nl/res/pub/27556/ 2010-09-27T00:00:00Z It is unclear how Th2 immunity is induced in response to allergens like house dust mite (HDM). Here, we show that HDM inhalation leads to the TLR4/MyD88-dependent recruitment of IL-4 competent basophils and eosinophils, and of inflammatory DCs to the draining mediastinal nodes. Depletion of basophils only partially reduced Th2 immunity, and depletion of eosinophils had no effect on the Th2 response. Basophils did not take up inhaled antigen, present it to T cells, or express antigen presentation machinery, whereas a population of FceRI+DCs readily did. Inflammatory DCs were necessary and sufficient for induction of Th2 immunity and features of asthma, whereas basophils were not required. We favor a model whereby DCs initiate and basophils amplify Th2 immunity to HDM allergen. Hammad, H. Plantinga, M. Deswarte, K. Pouliot, P. Kool, M. Willart, M.A. Muskens, F. Lambrecht, B.N.M. http://repub.eur.nl/res/pub/27418/ 2010-09-23T00:00:00Z To determine the role of vascular endothelial growth factor (Vegf) in embryonic erythroid development we have deleted or overexpressed Vegf specifically in the erythroid lineage using the EpoR-iCre transgenic line in combination with Cre/ loxP conditional gain and loss of function Vegf alleles. ROSA26 promoter-based expression of the Vegf164isoform in the early erythroid lineage resulted in a differentiation block of primitive erythroid progenitor (EryP) development and a partial block in definitive erythropoiesis between the erythroid burst-forming unit and erythroid colony-forming unit stages. Decreased mRNA expression levels of the key erythroid transcription factor Gata1 were causally linked to this phenotype. Conditional deletion of Vegf within the erythroid lineage was associated with increased Gata1 levels and increased erythroid differentiation. Expression of a ROSA26-based GATA2 transgene rescued Gata1 mRNA levels and target genes and restored erythroid differentiation in our Vegf gain of function model. These results demonstrate that Vegf modulates Gata1 expression levels in vivo and provides new molecular insight into Vegf's ability to modulate erythropoiesis. Drogat, B. Kalucka, J. Naessens, M. Ferrara, N. Klingmüller, U. Lambrecht, B.N.M. Nagy, A. Philipsen, S. Gutiérrez, L. Hammad, H. Goossens, S. Ghahremani, M.F. Bartunkova, S. Haigh, K. Deswarte, K. Nyabi, O. http://repub.eur.nl/res/pub/27369/ 2010-09-01T00:00:00Z The sensory neuropeptide calcitonin gene-related peptide (CGRP) plays a role in primary headaches, and CGRP receptor antagonists are effective in migraine treatment. CGRP is a potent vasodilator, raising the possibility that antagonism of its receptor could have cardiovascular effects. We therefore investigated the effects of the antimigraine CGRP receptor antagonist telcagepant (MK-0974) [N-[(3R,6S)-6-(2,3-difluorophenyl)-2-oxo-1-(2,2,2- trifluoroethyl) azepan-3-yl]-4-(2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridine-1- yl)piperidine-1-carboxamide] on human isolated coronary arteries. Arteries with different internal diameters were studied to assess the potential for differential effects across the coronary vascular bed. The concentration- dependent relaxation responses to human αCGRP were greater in distal coronary arteries (i.d. 600-1000 μm; Emax= 83 ± 7%) than proximal coronary arteries (i.d. 2-3 mm; Emax= 23 ± 9%), coronary arteries from explanted hearts (i.d. 3-5 mm; Emax= 11 ± 3%), and coronary arterioles (i.d. 200-300 μm; Emax= 15 ± 7%). Telcagepant alone did not induce contraction or relaxation of these coronary blood vessels. Pretreatment with telcagepant (10 nM to 1 μM) antagonized αCGRP-induced relaxation competitively in distal coronary arteries (pA2= 8.43 ± 0.24) and proximal coronary arteries and coronary arterioles (1 μM telcagepant, giving pKB= 7.89 ± 0.13 and 7.78 ± 0.16, respectively). αCGRP significantly increased cAMP levels in distal, but not proximal, coronary arteries, and this was abolished by pretreatment with telcagepant. Immunohistochemistry revealed the expression and colocalization of the CGRP receptor elements calcitonin-like receptor and receptor activity-modifying protein 1 in the smooth muscle cells in the media layer of human coronary arteries. These findings in vitro support the cardiovascular safety of CGRP receptor antagonists and suggest that telcagepant is unlikely to induce coronary side effects under normal cardiovascular conditions. Copyright Chan, K.Y. Edvinsson, L. Danser, A.H.J. MaassenVanDenBrink, A. Eftekhari, S. Kimblad, P.O. Kane, S.A. Lynch, J. Hargreaves, R.J. Vries, R. de Garrelds, I.M. Bogaerdt, A. van den http://repub.eur.nl/res/pub/27544/ 2010-09-01T00:00:00Z B-cell receptor (BCR)-mediated signals provide the basis for B-cell differentiation in the BM and subsequently into follicular, marginal zone, or B-1 B-cell subsets. We have previously shown that B-cell-specific expression of the constitutive active E41K mutant of the BCR-associated molecule Bruton's tyrosine kinase (Btk) leads to an almost complete deletion of immature B cells in the BM. Here, we report that low-level expression of the E41K or E41K-Y223F Btk mutants was associated with reduced follicular B-cell numbers and significantly increased proportions of B-1 cells in the spleen. Crosses with 3-83μδ and VH81X BCR Tg mice showed that constitutive active Btk expression did not change follicular, marginal zone, or B-1 B-cell fate choice, but resulted in selective expansion or survival of B-1 cells. Residual B cells were hyperresponsive and manifested sustained Ca2+mobilization. They were spontaneously driven into germinal center-independent plasma cell differentiation, as evidenced by increased numbers of IgM+plasma cells in spleen and BM and significantly elevated serum IgM. Because anti-nucleosome autoantibodies and glomerular IgM deposition were present, we conclude that constitutive Btk activation causes defective B-cell tolerance, emphasizing that Btk signals are essential for appropriate regulation of B-cell activation. Kersseboom, R. Kil, L. Flierman, R. Zee, M. van der Dingjan, G.M. Middendorp, S. Maas, A. Hendriks, R.W.