Tiotropium suppresses acetylcholine-induced release of chemotactic mediators in vitro

SummaryThe driving force in the progression of COPD is the development of exacerbations which are mostly the result of excessive inflammation. Bronchodilatators play an important role in the treatment of COPD. The reported reduction in exacerbation rates in COPD is due to the inhibition of vagal-mediated bronchoconstriction and mucus secretion. However, recent studies have highlighted the existence of muscarinic receptors on inflammatory cells and we have explored the possibility that tiotropium bromide might also inhibit neutrophil migration. We analysed the influence of tiotropium on the release of neutrophil chemotactic activity in response to acetylcholine (ACh) and the expression of muscarinic receptors on human alveolar macrophages (AM), A549 cells, MonoMac6 cells, and human lung fibroblasts. We found significant levels of all muscarinic receptor subtypes on all analysed cells except the fibroblasts. Fibroblasts expressed predominantly M2, receptors and did not release chemotactic activity. AM, A549 cells, and MonoMac6 cells released chemotactic active mediators after incubation with ACh. The secretion could be suppressed by more than 70% after coincubation with tiotropium. Tiotropium alone did not influence the granulocyte migration. Most of the chemotactic activity could be attributed to leukotriene B4 (LTB4). The release of interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1) was not induced by ACh. From this, we suggest that the suppression of the Ach-mediated release of chemotactic substances like LTB4 modulates the inflammatory reaction. This may contribute to the decreased rate of exacerbations in COPD, which was observed in clinical trials

Higher susceptibility to Fas ligand induced apoptosis and altered modulation of cell death by tumor necrosis factor-α in periarticular tenocytes from patients with knee joint osteoarthritis

The aim of the present study was to investigate the expression of Fas in periarticular tenocytes of patients with osteoarthritis (OA) and to study their susceptibility to Fas ligand-mediated apoptosis. Tendon samples were obtained from the quadriceps femoris muscle of patients with knee OA and used for histological evaluation, for immunohistochemical detection of Fas, and to establish tenocyte cultures. The expression of Fas mRNA was determined by quantitative PCR. Levels of soluble Fas and soluble tumour necrosis factor (TNF) receptor I were measured using ELISA. Apoptosis was induced with recombinant human Fas ligand and measured by a histone fragmentation assay and flow cytometry. The effects of TNF-α were studied by stimulation with TNF-α alone or 24 hours before the induction of apoptosis. Tendon samples from non-OA patients were used as controls. Histological evaluation revealed degenerative changes in the tendons of all OA patients but not in the controls. Fas was detected by immunohistochemistry in all specimens, but quantitative PCR revealed significantly higher levels of Fas mRNA in OA tenocytes. In contrast, lower levels of soluble Fas were found in OA tenocytes by ELISA. OA tenocytes were significantly more susceptible to Fas ligand induced apoptosis than were control cells. TNF-α reduced the Fas ligand induced apoptosis in OA tenocytes but had no effects on control tenocytes. These data suggest that knee OA is associated with higher susceptibility of periarticular tenocytes to Fas ligand induced apoptosis because of higher expression of Fas but lower levels of apoptosis-inhibiting soluble Fas. These changes may contribute to decreased cellularity in degenerative tendons and promote their rupturing. The antiapoptotic effects of TNF-α in OA tenocytes most likely reflect regenerative attempts and must be taken into account when anti-TNF strategies are considered for OA

S100A9 is indispensable for survival of pneumococcal pneumonia in mice

S100A8/A9 has important immunomodulatory roles in antibacterial defense, but its relevance in focal pneumonia caused by Streptococcus pneumoniae (S. pneumoniae) is understudied. We show that S100A9 was significantly increased in BAL fluids of patients with bacterial but not viral pneumonia and correlated with procalcitonin and sequential organ failure assessment scores. Mice deficient in S100A9 exhibited drastically elevated Zn$^{2+}$ levels in lungs, which led to bacterial outgrowth and significantly reduced survival. In addition, reduced survival of S100A9 KO mice was characterized by excessive release of neutrophil elastase, which resulted in degradation of opsonophagocytically important collectins surfactant proteins A and D. All of these features were attenuated in S. pneumoniae-challenged chimeric WT→S100A9 KO mice. Similarly, therapy of S. pneumoniae-infected S100A9 KO mice with a mutant S100A8/A9 protein showing increased half-life significantly decreased lung bacterial loads and lung injury. Collectively, S100A9 controls central antibacterial immune mechanisms of the lung with essential relevance to survival of pneumococcal pneumonia. Moreover, S100A9 appears to be a promising biomarker to distinguish patients with bacterial from those with viral pneumonia. Trial registration: Clinical Trials register (DRKS00000620)

表紙・目次 『第15回CEReS国際シンポジウム「環境リモートセンシングのこれま での成果とさらなる挑戦」』 2009年12月15日～16日 於千葉大学

Held on 15-16 December, 2009, Chiba Universit

Interleukin 6, lipopolysaccharide-binding protein and interleukin 10 in the prediction of risk and etiologic patterns in patients with community-acquired pneumonia: results from the German competence network CAPNETZ

<p>Abstract</p> <p>Background</p> <p>The aim of our study was to investigate the predictive value of the biomarkers interleukin 6 (IL-6), interleukin 10 (IL-10) and lipopolysaccharide-binding protein (LBP) compared with clinical CRB and CRB-65 severity scores in patients with community-acquired pneumonia (CAP).</p> <p>Methods</p> <p>Samples and data were obtained from patients enrolled into the German CAPNETZ study group. Samples (blood, sputum and urine) were collected within 24 h of first presentation and inclusion in the CAPNETZ study, and CRB and CRB-65 scores were determined for all patients at the time of enrollment. The combined end point representative of a severe course of CAP was defined as mechanical ventilation, intensive care unit treatment and/or death within 30 days. Overall, a total of 1,000 patients were enrolled in the study. A severe course of CAP was observed in 105 (10.5%) patients.</p> <p>Results</p> <p>The highest IL-6, IL-10 and LBP concentrations were found in patients with CRB-65 scores of 3-4 or CRB scores of 2-3. IL-6 and LBP levels on enrollment in the study were significantly higher for patients with a severe course of CAP than for those who did not have severe CAP. In receiver operating characteristic analyses, the area under the curve values for of IL-6 (0.689), IL-10 (0.665) and LPB (0.624) in a severe course of CAP were lower than that of CRB-65 (0.764) and similar to that of CRB (0.69). The accuracy of both CRB and CRB-65 was increased significantly by including IL-6 measurements. In addition, higher cytokine concentrations were found in patients with typical bacterial infections compared with patients with atypical or viral infections and those with infection of unknown etiology. LBP showed the highest discriminatory power with respect to the etiology of infection.</p> <p>Conclusions</p> <p>IL-6, IL-10 and LBP concentrations were increased in patients with a CRB-65 score of 3-4 and a severe course of CAP. The concentrations of IL-6 and IL-10 reflected the severity of disease in patients with CAP. The predictive power of IL-6, IL-10 and LBP for a severe course of pneumonia was lower than that of CRB-65. Typical bacterial pathogens induced the highest LBP, IL-6 and IL-10 concentrations.</p