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Biomedical subjects

Claus Kroegel

Publications and source records attributed to Claus Kroegel.

At least 19 recordsLinked to original sources
PubMed2007

Phosphodiesterase-4 inhibitors as a novel approach for the treatment of respiratory disease: cilomilast.

Phosphodiesterase-4 (PDE4) is an important cAMP-metabolising enzyme in immune and inflammatory cells, airway smooth muscle and pulmonary nerves. The phosphodiesterase 4 (PDE4) enzyme plays a significant role in modulating the activity of cAMP, an important second messenger that mediates the relaxation of airway smooth muscle and suppresses inflammatory cell function, thereby attenuating the inflammatory response. Selective inhibitors of this enzyme show a broad spectrum of activity in animal models of COPD and asthma. These drugs block the hydrolysis of cAMP via inhibition of PDE4 and are attractive candidates for novel anti-inflammatory drugs. At present, two second-generation PDE4 inhibitors for the treatment of COPD and asthma patients are being tested in clinical Phase III trials. The most advanced compound is the orally active, selective PDE4 inhibitor cilomilast (Ariflo, SB-207499, cis-4-cyano-4-[3-cyclopentyloxy-4-methoxyphenyl]-cyclohexanecarboxylic acid; GlaxoSmithKline). Cilomilast shows high selectivity for cAMP-specific PDE4, an isoenzyme that predominates in pro-inflammatory and immune cells and that is 10-fold more selective for PDE4D than for PDE4A, -B or -C. In vitro, cilomilast suppresses the activity of several pro-inflammatory and immune cells that have been implicated in the pathogenesis of asthma and COPD. Moreover, it is highly active in animal models of these diseases. Cilomilast has been shown to exert potent anti-inflammatory effects both in vitro and in vivo. It is orally active and may be effective in the treatment of asthma and COPD; however, complete assessment of the therapeutic value of this novel compound class must await the outcome of longer-term clinical trials. This review presents a summary of the preclinical and clinical profile of cilomilast in patients with COPD.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2006

Expression of metalloproteinase-7 (matrilysin) in human blood and bronchoalveolar gamma/delta T-lymphocytes. Selective upregulation by the soluble non-peptidic mycobacterial phosphoantigen (isopentenyl pyrophosphate).

Human gammadelta T-lymphocytes are believed to regulate local immune defense and enhance resistance against invading microbes, although their precise function remains unknown. Herein, we addressed the question whether gammadelta T-lymphocytes mediate these processes via synthesis of MMP-7, a protease closely associated with both epithelial repair and mucosal defense. Blood and bronchoalveolar gammadelta T-lymphocytes were cultured in the absence and presence of isopentenyl pyrophosphate (IPP) or TGF-beta1/IL-15 for 24 h, and assessed for the expression and synthesis of MMP-1, MMP-7, and MMP-9. Resting human gammadelta T-lymphocytes constitutively expressed MMP-9 mRNA, a marginal or no MMP-7 and MMP-1 mRNA. In the presence of IPP (3 microg/ml), expression of MMP-7 mRNA significantly increased, whereas TGF-beta1/IL-15 had no effect. Further, quiescent gammadelta T-lymphocytes obtained from bronchoalveolar lavage (BAL) fluid showed a weak or no MMP-7 mRNA signal which was raised significantly following stimulation with IPP. In Western blot analysis, a 28-kDa pro-matrilysin could be detected both in cell lysates (2 days) and supernatants (5 days) with a four- to sevenfold increased signal following IPP-stimulation of the gammadelta T-lymphocytes. In conclusion, the data demonstrate for the first time that both human blood and BAL gammadelta T-lymphocytes express MMP-7 mRNA and synthesize MMP-7-protein. This unfolds a new perspective for the understanding of gammadelta T-lymphocyte function.

Antigens, CD↗
PubMed2006

Immunopathogenesis of dilated cardiomyopathy. Evidence for the role of TH2-type CD4+T lymphocytes and association with myocardial HLA-DR expression.

BACKGROUND: An immunological pathogenesis underlying dilated cardiomyopathy and myocarditis has been suggested on the basis of the subtype of lymphocyte infiltrates and the degree of HLA expression in cardiac tissue. In the present study, we investigated the relation between the peripheral CD4+T-cell subset and the degree of HLA expression in the heart. METHODS: Fifty-four patients with heart insufficiency included in the study were biopsied after coronary heart disease had been excluded. Immunohistological staining of the left ventricular tissue were performed employing anti-CD3, -CD4, -CD8, -CD14, and HLA-DR monoclonal antibodies. Intracellular expression of IL-2, IL-4, IL-5, IFN-gamma, and TNF-alpha in peripheral CD4+T lymphocytes was determined using flow cytometry. The severity of heart insufficiency was determined by measurement of brain natriuretic peptide (BNP) and the NYHA class. On the basis of HLA expression in the heart, the patients were divided into three groups: Group I (mild-to-none), Group II (moderate), and Group III (strong-to-very strong). RESULTS: Of the 54 patients included in this study, 33 (61%) patients were diagnosed as having idiopathic dilated cardiomyopathy and 10 (18.5%) borderline or healing myocarditis according to the Dallas criteria. Both patient groups were found in all three HLA-DR groups. There was no difference in BNP level or NYHA class between the three groups. However, a significant difference in the proportion of CD4+T lymphocytes producing IL-2 (39.2 versus 21.8%), IFN-gamma (19.5 versus 7.8%), and TNF-alpha (35.8 versus 16.1%) between Groups I and III could be detected, whereas the distribution of IL-4 and IL-5 producing CD4+T lymphocytes was similar. The myocardium of Group III patients exhibited a significant higher number of CD3+T cells (11.4 versus 4.3 per mm2) and CD4+T cells (4.7 versus 0.8 per mm2) compared to Group I patients, while no difference existed with respect to CD8+T cells. CONCLUSION: High myocardial expression of the HLA-DR antigen is associated with an increase of peripheral-blood CD4+T lymphocytes expressing cytokines of the TH2 subset. The degree of HLA-DR expression is not associated with the degree of heart insufficiency or underlying diagnosis, but correlates with an increase of activated T cells in the myocardium. The data suggest that CD4+T lymphocytes infiltrating cardiac tissue may play a pathogenic role in dilated cardiomyopathy.

Adult↗
PubMed2005

Cis-9,trans-11-CLA exerts anti-inflammatory effects in human bronchial epithelial cells and eosinophils: comparison to trans-10,cis-12-CLA and to linoleic acid.

Interaction of eosinophils and bronchial epithelial cells plays a pivotal role in maintaining inflammatory airway disease. Since conjugated linoleic acids (CLA) are suggested to exert anti-inflammatory effects, one purpose of this study was to compare cis-9,trans-11-CLA and trans-10,cis-12-CLA with regard to their influence on the stimulus-induced activation of eosinophils. ECP (eosinophil cationic protein) released in co-culture of stimulated and CLA-treated eosinophils with stimulated bronchial epithelial cells (BEAS-2B) was measured and cis-9,trans-11-CLA was found to be most potent in inhibiting ECP formation. Further, expression of the activation markers CD69 and CD13 induced by various stimuli (TNF-alpha, IL-5, IL-3) was significantly reduced in the presence of cis-9,trans-11-CLA. Subsequently, various concentrations of cis-9,trans-11-CLA vs. linoleic acid (LA, cis-9,cis-12-octadecadienoic acid) were tested for the effect on proliferative response and release of the pro-inflammatory cytokine IL-8 in stimulated BEAS-2B. Addition of cis-9,trans-11-CLA attenuated cell growth and significantly reduced IL-8 production at mRNA and protein levels. In contrast, LA had a slight stimulating effect on proliferation and was less effective in reducing the cytokine release. It was demonstrated that the inhibitory effect of cis-9,trans-11-CLA on IL-8 production is mediated through activation of the nuclear receptor PPARgamma, since blocking the receptor with a selective antagonist (GW9662) restored the stimulus-induced enhancement in IL-8 mRNA expression and protein secretion. PPARgamma has previously been shown to be closely involved in the downregulation of inflammation during hyperresponsiveness related to pulmonary immune responses. Thus, targeting PPARgamma, cis-9,trans-11-CLA might be of therapeutic value in the focus of airway disease while ameliorating inflammatory processes by affecting epithelial and eosinophil functions.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2005

Interferon-alphacon-1 treatment of three patients with severe glucocorticoid-dependent asthma. Effect on disease control and systemic glucocorticosteroid dose.

We report herein the therapeutic effect of interferon (IFN)-alphacon in three patients with severe persistent asthma and long-term oral glucocorticoid treatment. IFN-alphacon (9 microg) administered subcutaneously thrice a week over a period of more than 24 months led to a substantial clinical improvement with regard to the number of daily asthma attacks, nighttime disturbance, emergency visits and hospitalizations. In addition, lung function and exercise capacity improved. At the same time, treatment with IFN allowed discontinuation of the daily glucocorticoid dose in all patients for the first time in more than 8 years. Our findings suggest that IFN-alphacon leads to a significant clinical improvement while at the same time allowing reduction and discontinuation of the glucocorticoid treatment in severe persistent glucocorticoid-dependent asthma.

Adrenal Cortex Hormones↗
PubMed2005

Accuracy of transthoracic sonography in excluding post-interventional pneumothorax and hydropneumothorax. Comparison to chest radiography.

OBJECTIVE: Transthoracic sonography (TS) has evolved as an important imaging technique for diagnosing pleural and pulmonary conditions. However, the value of TS in either excluding or diagnosing pneumothorax is still under debate. This study was conducted to examine whether TS could replace chest radiography for the diagnosis of post-interventional pneumothorax and hydropneumothorax. METHODS: 53 patients (21 females, 32 males; median age 64 years, range 37-94 years), 35 of whom underwent transbronchial biopsy (TBB) and 18 patients who had an ultrasound-guided chest tube placement (U-GCTP) were enrolled in the study. TS was performed three hours after either TBB or removal of a chest tube, followed by postero-anterior chest radiograph (CRX). If any discrepancy between TS, the clinical presentation and the CRX became apparent, either a lateral CRX or a computed tomography (CT) of the thorax was performed. TS was assessed according to the presence of the following criteria: (1) "gliding sign" of the pleural line, (2) comet tail artifacts, (3) reverberation artifacts, (4) air/fluid mirror, (5) hyperechoic reflectors within the pleural effusion and (6) "lung point". RESULTS: In four out of the 53 patients (7.5%) a post-interventional pneumothorax or hydropneumothorax occurred. One out of the 35 patients (2.9%) developed a pneumothorax after TBB, requiring chest tube placement. Three patients (16.7%) developed a hydropneumothorax due to U-GCTP which was detected by sonography but was missed by postero-anterior CRX in one patient. The sensitivity, specificity and accuracy of TS were 100% in excluding post-interventional pneumothorax/hydropneumothorax. CONCLUSION: TS is a cost-effective and safe bed-side-method, allowing for an immediate exclusion or diagnosis of post-interventional pneumothorax/hydropneumothorax in patients who have undergone TBB or U-GCTP. Thus, these preliminary results suggest that CXR may only be required in patients with pneumothorax diagnosed by TS in order to assess its extension or to exclude any discrepancy between the TS-result and the clinical presentation.

Adult↗
PubMed2005

Bilateral lung transplantation for severe persistent and difficult asthma.

Although asthma is listed as an indication for lung transplantation, only 2 cases have been reported to date. Here, we describe a 42-year-old woman with progressive, severe, persistent bronchial asthma resistant to high-dose oral steroids and adjuvant immunosuppressive therapy. Because conventional and experimental therapeutic strategies failed, the patient was listed for bilateral lung transplantation and received a transplant shortly thereafter. At 12 months after transplantation, her lung function parameters are normal and an asthma attack has not occurred since.

Adrenal Cortex Hormones↗
PubMed2004

Expression and synthesis of fibroblast growth factor-9 in human gammadelta T-lymphocytes. Response to isopentenyl pyrophosphate and TGF-beta1/IL-15.

Gammadelta T-lymphocytes are believed to play a role in maintaining the normal configuration of epithelial tissue. As little is known about the factors mediating this function, we addressed the question of whether gammadelta T-lymphocytes produce fibroblast growth factor (FGF)-9 as well as two other growth factors associated with epithelial tissue reconstitution. Blood gammadelta T cells isolated from healthy donors were grown in the presence of isopentenyl pyrophosphate (IPP) or transforming growth factor-beta1 (TGF-beta1)/interleukin-15 (IL-15) for 24 h and were assessed for the expression and synthesis of FGF-9, keratinocyte growth factor (KGF), and epidermal growth factor (EGF). Resting human gammadelta T cells constitutively expressed KGF and FGF-9 mRNA but no EGF mRNA. In the presence of IPP, FGF-9 mRNA expression significantly increased in a dose-dependent manner, expression of KGF remained unaltered, and EGF mRNA could not be detected. In contrast to IPP, stimulation of the cells with TGF-beta1/IL-15 did not alter FGF-9 expression. Moreover, stimulation with anti-CD3 does not induce FGF-9 expression but triggers a high signal of interferon-gamma mRNA. Western blot analysis of gammadelta T cell lysates, prepared 4 days following stimulation with IPP, showed an increase of FGF-9 protein as compared with control cells. In conclusion, the results demonstrate for the first time that human blood and bronchoalveolar lavage gammadelta T-lymphocytes are capable of expressing FGF-9. The data also provide novel evidence that immunoregulatory cells can synthesize FGF-9.

Blotting, Western↗
PubMed2004

Ancillary lung parenchymal findings at spiral CT scanning in pulmonary embolism. Relationship to chest sonography.

INTRODUCTION/OBJECTIVE: The aim of the study was to compare findings of transthoracic sonography (TS) and of spiral computed tomography (sCT) in patients with suspected pulmonary embolism (PE). METHODS AND PATIENTS: Peripheral parenchymal and pleural findings of TS and sCT were compared in 62 patients (25 females, 37 males; mean age 62.2 years) with suspected PE. RESULTS: In 39 patients PE was established, of whose pleura-based lesions could be detected by TS in 30 patients and by sCT in 31 patients. Whilst in three of the patients parenchymal lesions were exclusively detected by sonography, no peripheral abnormalities could be discovered with either technique in five patients. Among the nine patients lacking peripheral abnormalities on sonography, four revealed peripheral lesions in sCT. In 23 patients without PE, peripheral consolidations at CT were detected in six patients whereas two showed lesions on TS. With respect to the appearance, pleura-based wedge-shaped consolidations were the main parenchymal alterations (82.4% at TS, 66.1% at sCT) as compared with non-wedge-shaped consolidations (17.6% at TS, 33.9% at sCT). Peripheral lesions were located preferentially within the lower lobes. In addition, both localised and basal pleural effusion associated with PE could be demonstrated in 58.9% at TS and in 23.1% by sCT. DISCUSSIONS AND CONCLUSION: The study shows that in PE parenchymal and pleural changes are detectable by TS and sCT. If parenchymal findings are present at sCT, peripheral PE should be considered, even in the absence of directly visible emboli.

Adult↗
PubMed2003

Antiinflammatory effects of the phosphodiesterase-4 inhibitor cilomilast (Ariflo) in chronic obstructive pulmonary disease.

Cilomilast (Ariflo), a new oral phosphodiesterase-4 selective inhibitor, improves lung function in chronic obstructive pulmonary disease (COPD). We have evaluated its antiinflammatory effects in 59 patients with COPD randomized to receive cilomilast, 15 mg two times a day, or placebo for 12 weeks. Induced sputum differential cell counts were obtained at baseline and at five further visits. Interleukin-8 and neutrophil elastase were measured in sputum supernatant. Bronchial biopsies obtained at baseline and at Week 10 were immunostained and counted for neutrophils, CD8+ and CD4+ T-lymphocyte subsets, and CD68+ macrophages. Cells expressing the genes for interleukin-8 and tumor necrosis factor-alpha were identified by in situ hybridization and quantified. Compared with placebo, analysis of variance (ANOVA) of the change from baseline showed that cilomilast did not alter any sputum endpoint or FEV1. However, bronchial biopsies demonstrated that cilomilast treatment was associated with reductions in CD8+ (p = 0.001; ANOVA) and CD68+ cells (p < 0.05; ANOVA). In addition, by Poisson analysis, comparison of cell counts analyzed as a ratio of active to placebo demonstrated reductions of CD8+ (48% p < 0.01) and CD68+ (47% p = 0.001) cells. This is the first demonstration of reduction by any agent of airway tissue inflammatory cells characteristic of COPD. Phosphodiesterase-4 inhibitors represent a promising new class of substances for use in antiinflammatory treatment of this disease.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2003

Human gamma delta-T lymphocytes express and synthesize connective tissue growth factor: effect of IL-15 and TGF-beta 1 and comparison with alpha beta-T lymphocytes.

T lymphocytes bearing the gammadelta-TCR accumulate during wound healing and inflammation. However, the role of gammadelta-T lymphocytes in fibrogenic tissue reactions is not well understood. Therefore, we addressed the question of whether human gammadelta-T cells express and synthesize connective tissue growth factor (CTGF), a factor known to regulate fibrogenesis and wound healing. In addition, the lymphoblastic leukemia T cell line (Loucy) that possesses characteristics typical of gammadelta-T cells was used as a model to evaluate the regulation of CTGF gene expression. Blood gammadelta-T cells isolated from healthy donors were grown in the presence of IL-15/TGF-beta1 for 48 h and assessed for the expression and synthesis of CTGF. Nonstimulated human blood gammadelta-T cells and Loucy gammadelta-T cells expressed low levels of CTGF mRNA. Costimulation of the cells with IL-15 and TGF-beta1 resulted in a substantially increased level of CTGF mRNA expression within 4-8 h, and it remained elevated for at least 48 h. In contrast, no CTGF mRNA was detected when nonstimulated and stimulated human CD4+ alphabeta-T cells were analyzed. In addition, Western blot analysis of human gammadelta-T cell lysates prepared 4 days following stimulation with IL-15 and TGF-beta1 revealed a 38-kDa CTGF protein in cell lysates of human gammadelta-T cells. Detection was confirmed using Colo 849 fibroblasts, which can constitutively express high levels of CTGF. In conclusion, we herein present novel evidence that in contrast to CD4+ alphabeta-T cells human gammadelta-T cells are capable of expressing CTGF mRNA and synthesizing its corresponding protein, which supports the concept that gammadelta-T cells may contribute to wound healing or tissue fibrotic processes.

Blotting, Western↗
PubMed2003

Phenotypic and molecular characterization of CD103+ CD4+ T cells in bronchoalveolar lavage from patients with interstitial lung diseases.

BACKGROUND: The integrin CD103 is preferentially expressed on intraepithelial T lymphocytes, and cells expressing this integrin may play a regulatory role in the microenvironment of the epithelial cell layer. METHODS: The relative number of CD103(+)/CD4(+) T cells in the bronchoalveolar lavage was significantly elevated in all patients diagnosed with interstitial lung diseases compared with patients with other non-fibrotic disorders of the lung. RESULTS: Analysis by flow cytometry showed that the CD103(+) and the CD103(-) subpopulations were memory T cells based on the high expression of CD45RO(+). However, the CD103(+)/CD4(+) T cells were CD25(low), CD27(-), CD28(low), and CD62L(-), whereas the CD103(-)/CD4(+) T cells expressed CD25 and CD62L and were CD27(high) and CD28(high). In addition, the CD103(+)/CD4(+) T cells expressed significantly higher quantities of VLA-1 and CD101 than did CD103(-)/CD4(+) T cells. Reverse transcriptase polymerase chain reaction analysis of purified CD103(+) and CD103(-) CD4(+) T cells showed production of tumor necrosis factor (TNF) alpha-R-1 (p55), TNF-alpha-R-2 (p75), interferon gamma, interleukin-10, and TNF-alpha mRNA in both subpopulations. No interleukin-4 mRNA was detected in either subpopulation. CONCLUSIONS: CD103(+)/CD4(+) T cells represent a T-helper 1-like subpopulation in human lungs with a distinct effector phenotype. Despite the lack of CD27 and the low CD25 and CD28 expression, these cells show a high degree of activation. These results suggest that CD103 expressing CD4 T cells in the lung are continuously activated, long-living cells.

Antigens, CD↗
PubMed2003

Synovial fibroblasts and synovial macrophages from patients with rheumatoid arthritis and other inflammatory joint diseases show chromosomal aberrations.

Chromosomal aberrations were investigated in nuclei extracted from synovial tissue and first-passage synovial fibroblasts (P-1 SFB, 98% enrichment) or macrophages (P-1 Mphi) from patients with rheumatoid arthritis (n=10). The findings were compared with those in other rheumatic diseases (osteoarthritis, n=14; reactive arthritis, n=1), as well as with those in chronic obstructive pulmonary disease (n=8). Controls were paired peripheral blood lymphocytes from arthritic patients, synovial tissue or SFB/Mphi from joint trauma/normals (n=9), and peripheral blood monocytes from normal donors (n=10). GTG banding of metaphase chromosomes and interphase fluorescence in situ hybridization with centromere-specific probes were used. Comparable chromosomal aberrations were observed in synovial tissue and P-1 SFB of patients with rheumatoid arthritis, osteoarthritis, and reactive arthritis (polysomy 7 and aneusomies of chromosomes 4, 8, 9, 12, and 18). Notably, aneusomies of chromosomes 4, 6, 7, 8, 9, 11, 12, and/or X were also detected in P-1 synovial Mphi from rheumatoid arthritis (90% of the cases), osteoarthritis (93%), and reactive arthritis (1/1), as well as bronchial Mphi from chronic obstructive pulmonary disease (25%). No aberrations were detected in paired peripheral blood lymphocytes (except for one osteoarthritis case with a karyotype 45,X[10]/46,XX[17]), or in peripheral blood monocytes and synovial tissue of normals/joint trauma. Because Mphi aberrations were common to chronic joint and pulmonary disease, chronic inflammatory stress may induce chromosomal aberrations with potential functional relevance in local mesenchymal cells and infiltrating leukocytes in an organ-independent fashion.

Adult↗
PubMed2003

Differential regulation of aminopeptidase N (CD13) by transendothelial migration and cytokines on human eosinophils.

Aminopeptidase N (CD13) is a cell surface metalloprotease involved in growth regulation, tumor invasion, and down-regulation of regulatory peptides. CD13 expression on eosinophils in bronchoalveolar lavage (BAL) of asthmatics 10 minutes and 18 hours after segmental allergen provocation was significantly increased (+225% to +294%) compared to blood eosinophils. In vitro CD13 expression could be induced on blood eosinophils by transendothelial migration of the cells across interlenkin (IL) 1beta-activated human umbilical cord vein endothelial cells (HUVECs) as well as by the exposure to the cytokines IL-3, IL-5, and granulocyte-macrophage colony-stimulating factor (GM-CSF). The cytokines GM-CSF and IL-5 were significantly less effective in inducing CD13 compared to IL-3. The IL-3-induced expression of CD13 was decreased in the presence of the protein-synthesis inhibitor cycloheximide (-8.8%). Moreover, blocking of CD13 by the protease inhibitors actinonin and bestatin significantly enhanced migration (+40.0% to +80.0%) of eosinophils across HUVEC monolayers. In summary, the data suggest that CD13 is regulated both by the process of transmigration and by the cytokine IL-3. Further, CD13 itself seems to be involved in the process of eosinophil transmigration. aminopeptidase Nendothelial cellseosinophilsinterleukin-3interleukin-5transendothelial migration

Adult↗