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ABSTRACT: Selectins mediate the adhesion of leukocytes to activated endothelial cells and activated platelets. In addition to these cell-to-cell interactions, they influence the fibrin content and size of venous thrombi in different animal models. However, the exact role of selectins in human endotoxemia still remains unclear. We aimed to investigate the effect of selectin inhibition in lipopolysaccharide (LPS)-induced tissue factor (TF)-dependent activation of coagulation in a well-standardized model of human endotoxemia. To explore whether selectin blockade attenuates LPS-induced coagulation in humans, we performed a randomized, double-bind placebo-controlled crossover trial in 16 healthy male volunteers. All subjects received 2 ng/kg of LPS and, 10 min thereafter, a 15-min infusion of either 30 mg/kg of the pan-selectin antagonist bimosiamose or equal volumes of placebo in random order, with a washout period of 6 weeks between both periods. Treatment with bimosiamose had no significant effect on LPS-induced TF expression, as quantified by TF mRNA levels, or on LPS-induced coagulation response, reflected by increases in plasma thrombin-antithrombin (TAT) complexes and prothrombin fragment (F1 + 2) levels. Furthermore, bimosiamose did not affect the LPS-dependent changes in leukocyte subpopulations or the increase in platelet-leukocyte aggregates, as determined in the level of CD41+ monocytes. Finally, neither the LPS-induced release of tumor necrosis factor, interleukin 6, leukocyte expression of CD11b, nor intercellular adhesion molecule 1 were affected by administration of bimosiamose. The pan-selectin antagonist bimosiamose does not attenuate TF-triggered coagulation or inflammation in human endotoxemia. This indicates a minor influence of this selectin antagonist in this model. In addition, infusion of bimosiamose was safe and well tolerated in human endotoxemia.
Shock 05/2008; 29(4):475-82. · 2.85 Impact Factor
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ABSTRACT: Bimosiamose is a novel synthetic pan-selectin antagonist developed for the treatment of acute and chronic inflammatory disorders. Therefore the pharmacokinetics of Bimosiamose disodium were studied in healthy male volunteers after single and multiple subcutaneous injections. A randomized, double-blind, placebo-controlled dose escalation trial was carried out. The subjects received subcutaneous injections of placebo or 100, 200 or 300 mg Bimosiamose disodium into the abdomen. Plasma and urine concentrations of Bimosiamose were determined. The maximum plasma concentration was 2.17+/-0.70 microg/ml and the AUC(0-infinity) 11.1+/-2.9 h microg/ml after the highest dose on day 1 (mean+/-SD). For the apparent clearance CL/f 28.7+/-7.3 l/h and the terminal half life t(1/2) 3.7+/-0.6 h were calculated. The mean residence time MRT(infinity) of 5.5 to 6.3 h for s.c. injection exceeded that after i.v. infusion due to an extended absorption time. For multiple dosing, constant pre-dose concentrations of about 20 ng/ml may be reached after two subsequent doses of 200 or 300 mg Bimosiamose disodium once daily. Almost 15% of the administered drug was excreted unchanged in urine. Moreover, Bimosiamose was well tolerated.
Biopharmaceutics & Drug Disposition 01/2008; 28(9):475-84. · 2.07 Impact Factor
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ABSTRACT: Selectins mediate the adhesion of leukocytes to activated endothelial cells and activated platelets. In addition to these cell-to-cell interactions, they influence the fibrin content and size of venous thrombi in different animal models. However, the exact role of selectins in human endotoxemia still remains unclear. We aimed to investigate the effect of selectin inhibition in lipopolysaccharide (LPS)-induced tissue factor (TF)-dependent activation of coagulation in a well-standardized model of human endotoxemia. To explore whether selectin blockade attenuates LPS-induced coagulation in humans, we performed randomized, double-blind placebo-controlled crossover trial in 16 healthy male volunteers. All subjects received 2 ng/kg of LPS and, 10 min thereafter, a 15-min infusion of either 30 mg/kg of the pan-selectin antagonist bimosiamose or equal volumes of placebo in random order, with a washout period of 6 weeks between both periods. Treatment with bimosiamose had no significant effect on the LPS-induced TF expression, as quantified by TF mRNA levels, or on the LPS-induced procoagulant response, reflected by increases in plasma thrombin-antithrombin (TAT) complexes and prothrombin fragment (F1 + 2) levels. Furthermore, bimosiamose did not affect the LPS-dependent changes in leukocyte subpopulations or the increase in platelet-leukocyte aggregates, as determined in the level of CD41 monocytes. Finally, neither the LPS-induced release of tumor necrosis factor, interleukin 6, leukocyte expression of CD11b, nor intercellular adhesion molecule 1 was affected by administration of bimosiamose. The pan-selectin antagonist bimosiamose does not attenuate TF-triggered coagulation or inflammation in human endotoxemia. This indicates a minor influence of this selectin antagonist in this model. In addition, infusion of bimosiamose was safe and well tolerated in human endotoxemia.
Shock 09/2007; Publish Ahead of Print. · 2.85 Impact Factor
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ABSTRACT: Type II myosin is the molecular motor which drives contraction upon cyclic interaction with filamentous actin while consuming ATP. The contemporary crystallographic structure of the myosin subfragment-1 (S1) of myosin covers both the motor domain of the heavy chain (MHC) as well as the essential (ELC) and regulatory light chains (RLC). A part of the N-terminus of the ELC is, however, missing in the 3D-models of Type II myosin. The N-terminal domain of the ELC comprises interesting functional features since it binds to actin thus controlling myosin motor activity. For the first time, we modeled the missing 46 N-terminal amino acid of the ELC to the contemporary actin-myosin-S1 complex. We show a rod-like 91 A structure being long enough to bridge the gap between the ELC core of myosin-S1 and the appropriate binding site of the ELC on the actin filament.
Journal of Structural Biology 08/2007; 159(1):158-63. · 3.41 Impact Factor
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ABSTRACT: The aim of these first-in-human studies was to investigate the tolerability and the pharmacokinetics of bimosiamose disodium (TBC1269Z) administered by inhalation.
Two randomized, double-blind, placebo-controlled Phase I trials were performed in healthy males. In a single-dose escalating study 48 subjects received doses of 2-140 mg bimosiamose disodium by inhalation and in a multiple-dose study 32 subjects received 8-70 mg bimosiamose disodium twice daily. In both studies 4 ml of the drug solution was administered via nebulizer over 15 min. Adverse events, vital signs, ECG, clinical laboratory parameters and forced expiratory volume in 1 s (FEV(1)) data were recorded and nasopharyngeal examinations were performed to address the safety and tolerability. Blood was collected for the determination of plasma concentrations of bimosiamose.
All subjects completed the study. No deaths or severe adverse events occurred. Eleven mild adverse events occurred in the dose-escalation study and 34 in the multiple-dose study after inhalation of bimosiamose disodium. Adverse events were more frequent at the highest dose (140 mg) of the dose-escalation study. For placebo treatment one moderate adverse event was observed in the dose-escalation study after placebo treatment, eight mild and three moderate adverse events occurred in the multiple-dose study. Bimosiamose was detected in plasma (maximum concentration 64 ng ml(-1)) only at doses > or =50 mg given twice daily and 105 mg once daily. For the highest dose a median value of 5746 h ng ml(-1) was determined for the AUC over the entire period of treatment of the multiple-dose study.
The results suggest that single and multiple inhalation of bimosiamose disodium up to 70 mg is well tolerated in healthy males. Systemic bioavailability after inhalation is low.
British Journal of Clinical Pharmacology 05/2007; 63(4):451-8. · 2.96 Impact Factor
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Remo Kranich,
Anke S Busemann,
Daniel Bock,
Sabine Schroeter-Maas,
Diana Beyer,
Bo Heinemann,
Michael Meyer,
Katrin Schierhorn,
Rainer Zahlten, Gerhard Wolff,
Ewald M Aydt
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ABSTRACT: This report describes the first results of a rational hit-finding strategy to design novel small molecule antiinflammatory drugs targeting selectins, a family of three cellular adhesion molecules. Based on recent progress in understanding of molecular interaction between selectins and their natural ligands as well as progress in clinical development of synthetic antagonists like 1 (bimosiamose, TBC1269), this study was initiated to discover small molecule selectin antagonists with improved pharmacological properties. Considering 1 as template structure, a ligand-based approach followed by focused chemical synthesis has been applied to yield novel synthetic small molecules (MWr < 500) with a trihydroxybenzene motif, bearing neither peptidic nor glycosidic components, with nanomolar in vitro activity. Biological evaluation involves two kinds of in vitro assays, a static molecular binding assay, and a dynamic HL-60 cell attachment assay. As compared to controls, the novel compounds showed improved biological in vitro activity both under static and dynamic conditions.
Journal of Medicinal Chemistry 04/2007; 50(6):1101-15. · 5.25 Impact Factor
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ABSTRACT: Psoriasis is a systemic chronic inflammatory disorder. One of the major characteristics is an excess of infiltration of inflammatory cells, mainly lymphocytes, into the skin. Because the adhesion family of selectins is suggested to play a relevant role in this process, selectins have emerged as an interesting target for drug discovery and development in psoriasis. Different strategies targeting selectins have been described. This review discusses these approaches and summarises the current development of selectin antagonists for the treatment of psoriasis. An expert opinion will give the authors' personal opinion about selectin antagonism in psoriasis and which approach might be preferable.
Expert Opinion on Investigational Drugs 09/2006; 15(8):963-79. · 5.27 Impact Factor
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ABSTRACT: The selectin family of cell adhesion molecules (selectins) is comprised of three structurally related calciumdependent carbohydrate binding proteins, E-, P-, and L-selectin. Located on the surface of endothelial cells (E- and Pselectin), platelets (P-selectin) and of leucocytes (L-selectin), selectins are of vital importance for leukocyte recruitment and accumulation in the vasculature. Based on the unique architecture of the microvasculature of the lung, this task is achieved by two different types of selectin mediated functions (i) tethering and rolling of leukocytes on the pre- and post capillary pulmonary endothelium and in bronchial venules which are mediated by E-, P-, and L-selectin as well as (ii) retention of leukocytes in the pulmonary capillaries by L-selectin. Recent findings in preclinical and clinical research suggest a significant involvement of selectins in both acute and chronic inflammatory lung diseases such as acute lung injury (ALI), acute respiratory distress syndrome (ARDS), asthma bronchiale (Asthma), chronic obstructive pulmonary disease (COPD) or idiopathic pulmonary fibrosis (IPF). This review summarizes the current progress in understanding the role of selectins during inflammation in the lung and its potential impact for innovative therapeutic strategies.
Current Respiratory Medicine Reviews 07/2006; 2(3):339-354.
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Markus Friedrich,
Daniel Bock,
Sandra Philipp,
Nina Ludwig,
Robert Sabat,
Kerstin Wolk,
Sabine Schroeter-Maas,
Ewald Aydt,
Sewon Kang,
Tomas Norman Dam,
Rainer Zahlten,
Wolfram Sterry, Gerhard Wolff
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ABSTRACT: The selectin family of vascular cell adhesion molecules is comprised of structurally related carbohydrate binding proteins, which mediate the initial rolling of leukocytes on the activated vascular endothelium. Because this process is one of the crucial events in initiating and maintaining inflammation, selectins are proposed to be an attractive target for the development of new antiinflammatory therapeutics. Here, we demonstrate that the synthetic pan-selectin antagonist bimosiamose is effective in pre-clinical models of psoriasis as well as in psoriatic patients. In vitro bimosiamose proved to be inhibitory to E- or P-selectin dependent lymphocyte adhesion under flow conditions. Using xenogeneic transplantation models, bimosiamose reduced disease severity as well as development of psoriatic plaques in symptomless psoriatic skin. The administration of bimosiamose in patients suffering from psoriasis resulted in a reduction of epidermal thickness and lymphocyte infiltration. The clinical improvement was statistically significant (P=0.02) as analyzed by comparison of psoriasis area and severity index before and after treatment. Assessment of safety parameters showed no abnormal findings. These data suggest that pan-selectin antagonism may be a promising strategy for the treatment of psoriasis and other inflammatory diseases.
Archives for Dermatological Research 03/2006; 297(8):345-51. · 2.28 Impact Factor
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ABSTRACT: Asthma is characterized by increased recruitment of inflammatory cells from the circulation into the airways. As selectins mediate tethering and rolling of leukocytes on the vascular endothelium, they constitute a promising target for the therapeutic modulation of inflammation. We evaluated the effect of inhaled bimosiamose (TBC1269), a synthetic pan-selectin antagonist, on allergen-induced late asthmatic reactions (LAR) in mild asthmatics.
Twelve male subjects with mild allergic asthma (only beta-agonists prn) with demonstrable LAR (fall of FEV1 3-8h after allergen inhalation >15% of baseline) at screening completed a randomized, double-blind, placebo-controlled clinical cross-over-trial. Subjects were treated with inhaled bimosiamose 70 mg bid or matching placebo on days 1-3 and 70 mg once on the morning of day 4. On day 4 following the last inhalation of study drug, an allergen challenge was performed. The primary endpoint was the maximum fall in FEV1 between 3 and 8h after allergen inhalation on active treatment vs. placebo. Secondary endpoints included early asthmatic response, exhaled nitric oxide, and airway hyperresponsiveness to methacholine 24h post allergen.
Bimosiamose significantly attenuated the maximum LAR compared to placebo by 50.2% (placebo mean+/-SEM fall -13.10+/-2.30%, bimosiamose -6.52+/-3.86%, treatment effect p=0.045; linear mixed-effects model). There was no effect of active treatment on early asthmatic response, post allergen airway hyperresponsiveness or exhaled nitric oxide, and peripheral blood cells.
Administration of the pan-selectin antagonist bimosiamose is effective in a human allergen challenge model of asthma. The result of this proof-of-concept exploratory trial is the first study that demonstrates clinical efficacy of selectin-antagonists as novel therapeutic strategy in asthma.
Pulmonary Pharmacology & Therapeutics 02/2006; 19(4):233-41. · 2.80 Impact Factor
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ABSTRACT: Es wird eine Apparatur beschrieben, die es gestattet, den disponiblen Sauerstoff von leicht zersetzlichen höheren Seltenerdoxyden gasvolumetrisch zu bestimmen. Mit dieser Apparatur wurde das System PraseodymoxydNeodymoxyd analytisch-chemisch untersucht und gezeigt, daß — im Einklang mit einer früher auf Grund röntgenographischer Untersuchungen1) gegebenen Deutung — durch Neodymsesquioxyd die Bildung von Praseodymdioxyd innerhalb der Fluoritphase begünstigt wird.
Journal für praktische Chemie 11/2004; 6(5‐6):259 - 265.
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ABSTRACT: The tumor-suppressor gene p16INK4/CDKN2 (p16) is a cyclin-dependent kinase (cdk) inhibitor and important cell cycle regulator. Here, we show that adenovirus-mediated gene transfer of p16 (AdCMV.p16) into colon cancer cells induces uncoupling of S phase and mitosis and subsequently apoptosis. Flow cytometric analysis revealed that cells infected with AdCMV.p16 showed an initial G2-like arrest followed by S phase without intervening mitosis (DNA >4N). Using microscopic analysis, deformed polyploid cells were detectable only in cells infected with AdCMV.p16 but not in control-infected cells. Subsequently, AdCMV.p16-infected polyploid cells underwent apoptosis, as assessed by AnnexinV staining and DNA fragmentation, suggesting that cell cycle dysregulation is upstream of the onset of apoptosis. Treatment of mice with subcutaneously transplanted tumors of colorectal cancer cells with AdCMV.p16 but not AdCMV.p53 resulted in significantly reduced tumor volume and prolonged survival. Using an orthotopic model of liver metastasis, we observed both reduced local tumor growth and secondary intrahepatic metastasis after AdCMV.p16 treatment. Importantly, induction of apoptosis in vitro and reduction of tumor growth in vivo by p16 was p53- as well as bax-independent because identical results were obtained using cancer cells, either wild type or mutant for p53 or bax. The studies suggest that an AdCMV.p16-based treatment may be especially effective in patients with bax-negative colon cancer where overexpression of p53 appears not to be of therapeutic value.
Cancer Gene Therapy 08/2002; 9(8):641-50. · 2.80 Impact Factor
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ABSTRACT: Gene products of recombinant replication-deficient adenovirus vectors of the first generation (Ad vector) can induce cell cycle dysregulation and apoptosis after infection in eukaryotic cells. The mechanisms underlying this complex process are largely unknown. Therefore, we investigated the regulation of the pRb/E2F-1 complex, which controls transition from G(0)/G(1) to S phase of the cell cycle. As Ad vector infection results in a decrease in the number of cells in G(0)/G(1) phase of the cell cycle, we observed a decline of the pRb protein level and, surprisingly, also a decrease of the E2F-1 protein and mRNA level in infected cell lines. Furthermore, in contrast to the reduction of cells in the G(0)/G(1) phase we observed increased protein levels of p53 and p21 proteins. However, as experiments in p53 deficient cell lines indicated, the decrease of pRb and E2F-1 is independent of p53 and p21 expression. Moreover, results obtained with Rb deficient cell lines indicated that the reduced E2F-1 expression is independent of pRb. These results suggest that Ad vector-induced cell cycle dysregulation is associated with a specific downregulation of E2F-1 independent of Rb and p53 genomic status of cells.
Biochimica et Biophysica Acta 02/2002; 1542(1-3):106-15. · 4.66 Impact Factor
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ABSTRACT: Expression of the human atrial myosin light chain 1 (hALC-1) in the cardiac ventricle in vivo as well as in primary cultivated adult cardiomyocytes caused a pronounced positive inotropic effect. Therefore, it is one of the most promising candidate gene to treat congestive heart failure (CHF). In this work, we investigated, whether hALC-1 expression also modifies the energetic state of cardiomyocytes. Primary cultivated neonatal rat hearts cells (NRHC) were infected with adenoviral vectors (Ad vectors) containing a hALC-1 cDNA (AdCMV.hALC-1) or a control Ad vector. Infection efficiency of NRHC reached 100% at 50 multiplicity of infection (MOI). Interestingly and in contrast to primary cultures of liver cells, there were no cytotoxic side effects or induction of apoptosis up to MOI 50 in Ad vector infected NRHC. NRHC expressed large amounts of hALC-1 upon infection with AdCMV.hALC-1 which could easily been detected by protein staining and Western blot analysis. Analysis of intracellular hALC-1 localization by double-labeling immunofluorescence of AdCMV.hALC-1 infected cardiomyocytes revealed the typical myofibrillar striation pattern, as well as co-localization of hALC-1 with myosin heavy chains. There was no difference in the oxygen consumption between controls and AdCMV.hALC-1 infected NRHC. These data suggest that first: adenoviral vectors could be used as a safe and effective tool for gene transfer to cardiomyocytes, and second: that a positive inotropic effect of hALC-1 is not associated with enhanced oxygen consumption.
Journal of Cellular Biochemistry 02/2002; 86(3):422-31. · 2.87 Impact Factor
