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Grazyna Kwapiszewska,
Karolina Chwalek,
Leigh Matthew Marsh,
Malgorzata Wygrecka,
Jochen Wilhelm,
Johannes Best,
Bakytbek Egemnazarov,
Friederike Christine Weisel,
Sara Louise Osswald,
Ralph Theo Schermuly,
Andrea Olschewski,
Werner Seeger,
Norbert Weissmann, Oliver Eickelberg,
Ludger Fink
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ABSTRACT: Pulmonary arterial hypertension (PAH) is a life-threatening disorder that is characterized by pulmonary arterial smooth muscle cell (PASMC) hyperplasia. Until now, little was been known about early changes that underlie the manifestation of PAH. To characterize these early changes, we performed whole-genome microarray analysis of lungs from mice exposed to either 24 hours hypoxia or normoxia. TrkB, a member of the tyrosine kinase receptor family, and its ligand, brain-derived neurotrophic factor (BDNF), were strongly up-regulated in hypoxic mouse lungs, as well as in arteries of patients suffering from idiopathic PAH. BDNF stimulation of PASMC in vitro resulted in increased proliferation, TrkB and Erk1/2 phosphorylation, and nuclear translocation of the transcription factor early growth response factor 1 (Egr-1). In addition, increased Egr-1 expression was observed in idiopathic PAH lungs. The pro-proliferative effect of BDNF was attenuated by TrkB kinase inhibitor (K252a) or Erk1/2 inhibitor (U0126) pretreatment, and by knocking down Egr-1. Consequently, we have identified the BDNF-TrkB-Erk1/2 pathway as a proproliferative signaling pathway for PASMC in PAH. Interference with this pathway may thus serve as an attractive reverse remodeling approach.
American Journal Of Pathology 10/2012; · 4.89 Impact Factor
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ABSTRACT: Although TGF-β acts as a tumor suppressor in normal tissues and in early carcinogenesis, these tumor suppressor effects are lost in advanced malignancies. Single cell migration and epithelial-mesenchymal transition (EMT), both of which are regulated by TGF-β, are critical steps in mediating cancer progression. Here, we sought to identify novel direct targets of TGF-β signaling in lung cancer cells and have indentified the zyxin gene as a target of Smad3-mediated TGF-β1 signaling. Zyxin concentrates at focal adhesions and along the actin cytoskeleton; as such, we hypothesized that cytoskeletal organization, motility, and EMT in response to TGF-β1 might be regulated by zyxin expression. We show that TGF-β1 treatment of lung cancer cells caused rapid phospho-Smad3-dependent expression of zyxin. Zyxin expression was critical for the formation and integrity of cell adherens junctions. Silencing of zyxin decreased expression of the focal adhesion protein vasodilator-activated phospho-protein (VASP), although the formation and morphology of focal adhesions remained unchanged. Zyxin-depleted cells displayed significantly increased integrin α5β1 levels, accompanied by enhanced adhesion to fibronectin and acquisition of a mesenchymal phenotype in response to TGF-β1. Zyxin silencing led to elevated integrin α5β1-dependent single cell motility. Importantly, these features are mirrored in the K-ras-driven mouse model of lung cancer. Here, lung tumors revealed decreased levels of both zyxin and phospho-Smad3 when compared with normal tissues. Our data thus demonstrate that zyxin is a novel functional target and effector of TGF-β signaling in lung cancer. By regulating cell-cell junctions, integrin α5β1 expression, and cell-extracellular matrix adhesion, zyxin may regulate cancer cell motility and EMT during lung cancer development and progression.
Journal of Biological Chemistry 07/2012; 287(37):31393-405. · 4.77 Impact Factor
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ABSTRACT: Tissue-specific transcripts are likely to be of importance for the corresponding organ. While attempting to define the specific transcriptome of the human lung, we identified the transcript of a yet uncharacterized protein, SFTA2. In silico analyses, biochemical methods, fluorescence imaging and animal challenge experiments were employed to characterize SFTA2. Human SFTA2 is located on Chr. 6p21.33, a disease-susceptibility locus for diffuse panbronchiolitis. RT-PCR verified the abundance of SFTA2-specific transcripts in human and mouse lung. SFTA2 is synthesized as a hydrophilic precursor releasing a 59 amino acid mature peptide after cleavage of an N-terminal secretory signal. SFTA2 has no recognizable homology to other proteins while orthologues are present in all mammals. SFTA2 is a glycosylated protein and specifically expressed in nonciliated bronchiolar epithelium and type II pneumocytes. In accordance with other hydrophilic surfactant proteins, SFTA2 did not colocalize with lamellar bodies but colocalized with golgin97 and clathrin-labelled vesicles, suggesting a classical secretory pathway for its expression and secretion. In the mouse lung, Sfta2 was significantly downregulated after induction of an inflammatory reaction by intratracheal lipopolysaccharides paralleling surfactant proteins B and C but not D. Hyperoxia, however, did not alter SFTA2 mRNA levels. We have characterized SFTA2 and present it as a novel unique secretory peptide highly expressed in the lung.
PLoS ONE 01/2012; 7(6):e40011. · 4.09 Impact Factor
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EMBO Molecular Medicine 08/2011; 3(10):575-7. · 10.33 Impact Factor
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Qiyuan Zhou,
Annie Pardo,
Melanie Königshoff, Oliver Eickelberg,
G R Scott Budinger,
Krishna Thavarajah,
Cara J Gottardi,
Jonathan Jones,
John Varga,
Moises Selman,
Jacob I Sznajder,
J Usha Raj,
Guofei Zhou
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ABSTRACT: Idiopathic pulmonary fibrosis (IPF) is characterized by exaggerated fibroblast proliferation and accumulation of collagens and fibronectin. The extracellular fibronectin and collagen network is regulated by von Hippel-Lindau protein (pVHL). However, it is unknown whether pVHL contributes to pulmonary fibrosis. We found that lungs from patients with IPF expressed increased levels of pVHL in fibroblastic foci. Bleomycin treatment also induced pVHL in lung fibroblasts, but not in alveolar type II cells. Overexpression of pVHL increased lung fibroblast proliferation, protein abundance of fibronectin and collagen, and extracellular fibronectin. In addition, overexpression of pVHL induced expression of the α5 integrin subunit. Overexpression of pVHL did not alter hypoxia-inducible factor luciferase reporter activity and mRNA expression of vascular endothelial growth factor. Fibroblasts overexpressing pVHL were more sensitive to RGD peptide-mediated reduction in proliferation. Activating α5 and β1 integrin increased proliferation of fibroblasts overexpressing pVHL and those cells were more resistant to the inhibition of α5 integrin. Overexpression of pVHL also increased activation of focal adhesion kinase (FAK). Moreover, suppression of pVHL prevented TGF-β1-induced proliferation of mouse embryonic fibroblasts. Taken together, our results indicate that elevated expression of pVHL results in the aberrant fibronectin expression, activation of integrin/FAK signaling, fibroblast proliferation, and fibrosis.
The FASEB Journal 06/2011; 25(9):3032-44. · 5.71 Impact Factor
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Soni Savai Pullamsetti,
Rajkumar Savai,
Rio Dumitrascu,
Bhola Kumar Dahal,
Jochen Wilhelm,
Melanie Konigshoff,
Dariusz Zakrzewicz,
Hossein Ardeschir Ghofrani,
Norbert Weissmann, Oliver Eickelberg,
Andreas Guenther,
James Leiper,
Werner Seeger,
Friedrich Grimminger,
Ralph Theo Schermuly
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ABSTRACT: Idiopathic pulmonary fibrosis (IPF) is a progressive, dysregulated response to alveolar injury that culminates in compromised lung function from excess extracellular matrix production. Associated with high morbidity and mortality, IPF is generally refractory to current pharmacological therapies. We examined fibrotic lungs from mice and from patients with IPF and detected increased expression of dimethylarginine dimethylaminohydrolases (DDAHs)--key enzymes that metabolize asymmetric dimethylarginine (ADMA), which is an endogenous inhibitor of nitric oxide synthase, to form l-citrulline and dimethylamine. DDAHs are up-regulated in primary alveolar epithelial type II cells from these mice and patients where they are colocalized with inducible nitric oxide synthase. In cultured alveolar epithelial type II cells from bleomycin-induced fibrotic mouse lungs, inhibition of DDAH suppressed proliferation and induced apoptosis in an ADMA-dependent manner. In addition, DDAH inhibition reduced collagen production by fibroblasts in an ADMA-independent but transforming growth factor/SMAD-dependent manner. In mice with bleomycin-induced pulmonary fibrosis, the DDAH inhibitor L-291 reduced collagen deposition and normalized lung function. In bleomycin-induced fibrosis, inducible nitric oxide synthase inhibition decreased fibrosis, but an even stronger reduction was observed after inhibition of DDAH. Thus, DDAH inhibition reduces fibroblast-induced collagen deposition in an ADMA-independent manner and reduces abnormal epithelial proliferation in an ADMA-dependent manner, offering a possible therapeutic avenue for attenuation of pulmonary fibrosis.
Science translational medicine 06/2011; 3(87):87ra53. · 7.80 Impact Factor
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ABSTRACT: Dimethylarginines are inhibitors of NO synthesis and are involved in the pathogenesis of vascular diseases. In this study, we ask the question if asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) levels change during fatal and reversible acute rejection, and contribute to the pathogenesis of chronic vasculopathy.
The Dark Agouti to Lewis rat strain combination was used to investigate fatal acute rejection. Fischer 344 kidneys were transplanted to Lewis rats to study reversible acute rejection episode and the process of chronic rejection. Isograft recipients and untreated Lewis rats were used as controls. l-arginine derivatives were determined by HPLC, and ADMA-metabolizing enzymes were studied by quantitative RT-PCR and western blotting.
Renal transplantation transiently increased dimethylarginine levels independent of acute rejection. ADMA plasma levels did not importantly differ between recipients undergoing fatal or reversible acute rejection, whereas SDMA was even lower in recipients of Fisher 344 grafts. In comparison to isograft recipients, ADMA and SDMA levels were slightly elevated during reversible, but not during the process of chronic rejection. Increased dimethylarginine levels, however, did not block NO synthesis. Interestingly, protein methylation, but not ADMA degradation, was increased in allografts.
Our data do not support the concept that renal allografts are protected from fatal rejection by dimethylarginines. Dimethylarginines may play a role in triggering chronic rejection, but a contribution to vascular remodelling itself is improbable. In contrast, differential arginine methylation of yet unknown proteins by PRMT1 may be involved in the pathogenesis of acute and chronic rejection.
Nephrology Dialysis Transplantation 01/2011; 26(1):124-35. · 3.40 Impact Factor
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Veronica Marcos,
Zhe Zhou,
Ali Önder Yildirim,
Alexander Bohla,
Andreas Hector,
Ljubomir Vitkov,
Eva-Maria Wiedenbauer,
Wolf Dietrich Krautgartner,
Walter Stoiber,
Bernd H Belohradsky,
Nikolaus Rieber,
Michael Kormann,
Barbara Koller,
Adelbert Roscher,
Dirk Roos,
Matthias Griese, Oliver Eickelberg,
Gerd Döring,
Marcus A Mall,
Dominik Hartl
Nature medicine 01/2011; 17(7):899. · 27.14 Impact Factor
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Andreas Hector,
Michael S D Kormann,
Ines Mack,
Philipp Latzin,
Carmen Casaulta,
Elisabeth Kieninger,
Zhe Zhou,
Ali Ö Yildirim,
Alexander Bohla,
Nikolaus Rieber,
Matthias Kappler,
Barbara Koller,
Ernst Eber,
Olaf Eickmeier,
Stefan Zielen, Oliver Eickelberg,
Matthias Griese,
Marcus A Mall,
Dominik Hartl
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ABSTRACT: The chitinase-like protein YKL-40 was found to be increased in patients with severe asthma and chronic obstructive pulmonary disease (COPD), two disease conditions featuring neutrophilic infiltrates. Based on these studies and a previous report indicating that neutrophils secrete YKL-40, we hypothesized that YKL-40 plays a key role in cystic fibrosis (CF) lung disease, a prototypic neutrophilic disease. The aim of this study was (i) to analyze YKL-40 levels in human and murine CF lung disease and (ii) to investigate whether YKL-40 single-nucleotide polymorphisms (SNPs) modulate CF lung disease severity. YKL-40 protein levels were quantified in serum and sputum supernatants from CF patients and control individuals. Levels of the murine homologue BRP-39 were analyzed in airway fluids from CF-like βENaC-Tg mice. YKL-40SNPs were analyzed in CF patients. YKL-40 levels were increased in sputum supernatants and in serum from CF patients compared to healthy control individuals. Within CF patients, YKL-40 levels were higher in sputum than in serum. BRP-39 levels were increased in airways fluids from βENaC-Tg mice compared to wild-type littermates. In both CF patients and βENaC-Tg mice, YKL-40/BRP-39 airway levels correlated with the severity of pulmonary obstruction. Two YKL-40 SNPs (rs871799 and rs880633) were found to modulate age-adjusted lung function in CF patients. YKL-40/BRP-39 levelsare increased in human and murine CF airway fluids, correlate with pulmonary function and modulate CF lung disease severity genetically. These findings suggest YKL-40 as a potential biomarker in CF lung disease.
PLoS ONE 01/2011; 6(9):e24399. · 4.09 Impact Factor
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Yingze Zhang,
Daniel Handley,
Tommy Kaplan,
Haiying Yu,
Abha S Bais,
Thomas Richards,
Kusum V Pandit,
Qilu Zeng,
Panayiotis V Benos,
Nir Friedman, Oliver Eickelberg,
Naftali Kaminski
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ABSTRACT: Transforming growth factor beta 1 (TGFβ1) plays a major role in many lung diseases including lung cancer, pulmonary hypertension, and pulmonary fibrosis. TGFβ1 activates a signal transduction cascade that results in the transcriptional regulation of genes in the nucleus, primarily through the DNA-binding transcription factor SMAD3. The objective of this study is to identify genome-wide scale map of SMAD3 binding targets and the molecular pathways and networks affected by the TGFβ1/SMAD3 signaling in lung epithelial cells.
We combined chromatin immunoprecipitation with human promoter region microarrays (ChIP-on-chip) along with gene expression microarrays to study global transcriptional regulation of the TGFβ1/SMAD3 pathway in human A549 alveolar epithelial cells. The molecular pathways and networks associated with TGFβ1/SMAD3 signaling were identified using computational approaches. Validation of selected target gene expression and direct binding of SMAD3 to promoters were performed by quantitative real time RT-PCR and electrophoretic mobility shift assay on A549 and human primary lung epithelial cells.
Known TGFβ1 target genes such as SERPINE1, SMAD6, SMAD7, TGFB1 and LTBP3, were found in both ChIP-on-chip and gene expression analyses as well as some previously unrecognized targets such as FOXA2. SMAD3 binding of FOXA2 promoter and changed expression were confirmed. Computational approaches combining ChIP-on-chip and gene expression microarray revealed multiple target molecular pathways affected by the TGFβ1/SMAD3 signaling. Identification of global targets and molecular pathways and networks associated with TGFβ1/SMAD3 signaling allow for a better understanding of the mechanisms that determine epithelial cell phenotypes in fibrogenesis and carcinogenesis as does the discovery of the direct effect of TGFβ1 on FOXA2.
PLoS ONE 01/2011; 6(5):e20319. · 4.09 Impact Factor
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ABSTRACT: Idiopathic pulmonary fibrosis (IPF) has a poor prognosis and limited responsiveness to available treatments. It is characterised by epithelial cell injury, fibroblast activation and proliferation and extracellular matrix deposition. Serotonin (5-hydroxytryptamine; 5-HT) induces fibroblast proliferation via the 5-HTR(2A) and 5-HTR(2B) receptors, but its pathophysiological role in IPF remains unclear. A study was undertaken to determine the expression of 5-HT receptors in IPF and experimental lung fibrosis and to investigate the effects of therapeutic inhibition of 5-HTR(2A/B) signalling on lung fibrosis in vivo and in vitro.
Quantitative RT-PCR showed that the expression of 5-HTR(1A/B) and 5-HTR(2B) was significantly increased in the lungs of patients with IPF (n=12) and in those with non-specific interstitial pneumonia (NSIP, n=6) compared with transplant donors (n=12). The expression of 5-HTR(2A) was increased specifically in IPF lungs but not in NSIP lungs. While 5-HTR(2A) protein largely localised to fibroblasts, 5-HTR(2B) localised to the epithelium. To assess the effects of 5HTR(2A/B) inhibition on fibrogenesis in vivo, mice were subjected to bleomycin-induced lung fibrosis and treated with the 5-HTR(2A/B) antagonist terguride (or vehicle) in a therapeutic approach (days 14-28 after bleomycin). Terguride-treated mice had significantly improved lung function and histology and decreased collagen content compared with vehicle-treated mice. Functional in vitro studies showed that terguride is a potent inhibitor of transforming growth factor β(1)- or WNT3a-induced collagen production.
The studies revealed an increased expression of 5-HTR(2A) specifically in IPF. Blockade of 5-HTR(2A/B) signalling by terguride reversed lung fibrosis and is thus a promising therapeutic approach for IPF.
Thorax 11/2010; 65(11):949-55. · 6.84 Impact Factor
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Nikolaus Kneidinger,
Ali Önder Yildirim,
Jens Callegari,
Shinji Takenaka,
Maria Magdalena Stein,
Rio Dumitrascu,
Alexander Bohla,
Ken R Bracke,
Rory E Morty,
Guy G Brusselle,
Ralph Theo Schermuly, Oliver Eickelberg,
Melanie Königshoff
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ABSTRACT: Chronic obstructive pulmonary disease (COPD) is a devastating disease, for which no causal therapy is available.
To characterize WNT/β-catenin signaling in COPD in humans and elucidate its potential role as a preventive and therapeutic target in experimental emphysema in mice.
The expression, localization, and activity of WNT/β-catenin signaling was assessed in 12 COPD and 12 transplant donor samples using quantitative reverse transcriptase polymerase chain reaction, immunohistochemistry, and Western blotting. The role of WNT/β-catenin signaling was assessed in elastase- and cigarette smoke-induced emphysema and therapeutic modulation thereof in elastase-induced emphysema in TOPGAL reporter and wild-type mice in vivo.
No differences in the mRNA expression profile of the main WNT/β-catenin signaling components were observed comparing COPD and donor lung homogenates. Immunohistochemical analysis revealed reduced numbers of nuclear β-catenin-positive alveolar epithelial cells in COPD. Similarly, WNT/β-catenin signaling was down-regulated in both experimental emphysema models. Preventive and therapeutic, WNT/β-catenin activation by lithium chloride attenuated experimental emphysema, as assessed by decreased airspace enlargement, improved lung function, reduced collagen content, and elevated expression of alveolar epithelial cell markers.
Decreased WNT/β-catenin signaling is involved in parenchymal tissue destruction and impaired repair capacity in emphysema. These data indicate a crucial role of WNT/β-catenin signaling in lung repair mechanisms in vivo, and highlight WNT/β-catenin activation as a future therapeutic approach for emphysema.
American Journal of Respiratory and Critical Care Medicine 10/2010; 183(6):723-33. · 11.08 Impact Factor
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Sevdalina Nikolova,
Andreas Guenther,
Rajkumar Savai,
Norbert Weissmann,
Hossein A Ghofrani,
Melanie Konigshoff, Oliver Eickelberg,
Walter Klepetko,
Robert Voswinckel,
Werner Seeger,
Friedrich Grimminger,
Ralph T Schermuly,
Soni S Pullamsetti
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ABSTRACT: Idiopathic Pulmonary Fibrosis (IPF) is an unresolved clinical issue. Phosphodiesterases (PDEs) are known therapeutic targets for various proliferative lung diseases. Lung PDE6 expression and function has received little or no attention. The present study aimed to characterize (i) PDE6 subunits expression in human lung, (ii) PDE6 subunits expression and alteration in IPF and (iii) functionality of the specific PDE6D subunit in alveolar epithelial cells (AECs).
PDE6 subunits expression in transplant donor (n = 6) and IPF (n = 6) lungs was demonstrated by real-time quantitative (q)RT-PCR and immunoblotting analysis. PDE6D mRNA and protein levels and PDE6G/H protein levels were significantly down-regulated in the IPF lungs. Immunohistochemical analysis showed alveolar epithelial localization of the PDE6 subunits. This was confirmed by qRT-PCR from human primary alveolar type (AT)II cells, demonstrating the down-regulation pattern of PDE6D in IPF-derived ATII cells. In vitro, PDE6D protein depletion was provoked by transforming growth factor (TGF)-β1 in A549 AECs. PDE6D siRNA-mediated knockdown and an ectopic expression of PDE6D modified the proliferation rate of A549 AECs. These effects were mediated by increased intracellular cGMP levels and decreased ERK phosphorylation.
Collectively, we report previously unrecognized PDE6 expression in human lungs, significant alterations of the PDE6D and PDE6G/H subunits in IPF lungs and characterize the functional role of PDE6D in AEC proliferation.
Respiratory research 10/2010; 11:146. · 3.36 Impact Factor
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Matthias Hecker,
Zbigniew Zaslona,
Grazyna Kwapiszewska,
Gero Niess,
Anna Zakrzewicz,
Eduard Hergenreider,
Jochen Wilhelm,
Leigh M Marsh,
Daniel Sedding,
Walter Klepetko,
Jürgen Lohmeyer,
Stefanie Dimmeler,
Werner Seeger,
Norbert Weissmann,
Ralph T Schermuly,
Nikolaus Kneidinger, Oliver Eickelberg,
Rory E Morty
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ABSTRACT: Idiopathic pulmonary arterial hypertension (IPAH) is characterized by medial hypertrophy due to pulmonary artery smooth muscle cell (paSMC) hyperplasia. Inflammation is proposed to play a role in vessel remodeling associated with IPAH. IL-13 is emerging as a regulator of tissue remodeling; however, the contribution of the IL-13 system to IPAH has not been assessed.
The objective of this study was to assess the possible contribution of the IL-13 system to IPAH.
Expression and localization of IL-13, and IL-13 receptors IL-4R, IL-13Rα1, and IL-13Rα2 were assessed by real-time reverse transcription-polymerase chain reaction, immunohistochemistry, and flow cytometry in lung tissue, paSMC, and microdissected vascular lesions from patients with IPAH, and in lung tissue from rodents with hypoxia- or monocrotaline-induced pulmonary hypertension. A whole-genome microarray analysis was used to study IL-13-regulated genes in paSMC.
Pulmonary expression of the IL-13 decoy receptor IL-13Rα2 was up-regulated relative to that of the IL-13 signaling receptors IL-4R and IL-13Rα1 in patients with IPAH and in two animal models of IPAH. IL-13, signaling via STAT3 and STAT6, suppressed proliferation of paSMC by promoting G(0)/G(1) arrest. Whole-genome microarrays revealed that IL-13 suppressed endothelin-1 production by paSMC, suggesting that IL-13 controlled paSMC growth by regulating endothelin production. Ectopic expression of the il13ra2 gene resulted in partial loss of paSMC growth control by IL-13 and blunted IL-13 suppression of endothelin-1 production by paSMC, whereas small-interfering RNA knockdown of il13ra2 gene expression had the opposite effects.
The IL-13 system is a novel regulator of paSMC growth. Dysregulation of IL-13 receptor expression in IPAH may partially underlie smooth muscle hypertrophy associated with pathological vascular remodeling in IPAH.
American Journal of Respiratory and Critical Care Medicine 09/2010; 182(6):805-18. · 11.08 Impact Factor
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Veronica Marcos,
Zhe Zhou,
Ali Onder Yildirim,
Alexander Bohla,
Andreas Hector,
Ljubomir Vitkov,
Eva-Maria Wiedenbauer,
Wolf Dietrich Krautgartner,
Walter Stoiber,
Bernd H Belohradsky,
Nikolaus Rieber,
Michael Kormann,
Barbara Koller,
Adelbert Roscher,
Dirk Roos,
Matthias Griese, Oliver Eickelberg,
Gerd Döring,
Marcus A Mall,
Dominik Hartl
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ABSTRACT: Upon activation, neutrophils release DNA fibers decorated with antimicrobial proteins, forming neutrophil extracellular traps (NETs). Although NETs are bactericidal and contribute to innate host defense, excessive NET formation has been linked to the pathogenesis of autoinflammatory diseases. However, the mechanisms regulating NET formation, particularly during chronic inflammation, are poorly understood. Here we show that the G protein-coupled receptor (GPCR) CXCR2 mediates NET formation. Downstream analyses showed that CXCR2-mediated NET formation was independent of NADPH oxidase and involved Src family kinases. We show the pathophysiological relevance of this mechanism in cystic fibrosis lung disease, characterized by chronic neutrophilic inflammation. We found abundant NETs in airway fluids of individuals with cystic fibrosis and mouse cystic fibrosis lung disease, and NET amounts correlated with impaired obstructive lung function. Pulmonary blockade of CXCR2 by intra-airway delivery of small-molecule antagonists inhibited NET formation and improved lung function in vivo without affecting neutrophil recruitment, proteolytic activity or antibacterial host defense. These studies establish CXCR2 as a receptor mediating NADPH oxidase-independent NET formation and provide evidence that this GPCR pathway is operative and druggable in cystic fibrosis lung disease.
Nature medicine 09/2010; 16(9):1018-23. · 27.14 Impact Factor
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Kusum V Pandit,
David Corcoran,
Hanadie Yousef,
Manohar Yarlagadda,
Argyris Tzouvelekis,
Kevin F Gibson,
Kazuhisa Konishi,
Samuel A Yousem,
Mandal Singh,
Daniel Handley,
Thomas Richards,
Moises Selman,
Simon C Watkins,
Annie Pardo,
Ahmi Ben-Yehudah,
Demosthenes Bouros, Oliver Eickelberg,
Prabir Ray,
Panayiotis V Benos,
Naftali Kaminski
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ABSTRACT: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and usually lethal fibrotic lung disease characterized by profound changes in epithelial cell phenotype and fibroblast proliferation.
To determine changes in expression and role of microRNAs in IPF.
RNA from 10 control and 10 IPF tissues was hybridized on Agilent microRNA microarrays and results were confirmed by quantitative real-time polymerase chain reaction and in situ hybridization. SMAD3 binding to the let-7d promoter was confirmed by chromatin immunoprecipitation, electrophoretic mobility shift assay, luciferase assays, and reduced expression of let-7d in response to transforming growth factor-beta. HMGA2, a let-7d target, was localized by immunohistochemistry. In mice, let-7d was inhibited by intratracheal administration of a let-7d antagomir and its effects were determined by immunohistochemistry, immunofluorescence, quantitative real-time polymerase chain reaction, and morphometry. Measurements and Main
Eighteen microRNAs including let-7d were significantly decreased in IPF. Transforming growth factor-beta down-regulated let-7d expression, and SMAD3 binding to the let-7d promoter was demonstrated. Inhibition of let-7d caused increases in mesenchymal markers N-cadherin-2, vimentin, and alpha-smooth muscle actin (ACTA2) as well as HMGA2 in multiple epithelial cell lines. let-7d was significantly reduced in IPF lungs and the number of epithelial cells expressing let-7d correlated with pulmonary functions. HMGA2 was increased in alveolar epithelial cells of IPF lungs. let-7d inhibition in vivo caused alveolar septal thickening and increases in collagen, ACTA2, and S100A4 expression in SFTPC (pulmonary-associated surfactant protein C) expressing alveolar epithelial cells.
Our results indicate a role for microRNAs in IPF. The down-regulation of let-7d in IPF and the profibrotic effects of this down-regulation in vitro and in vivo suggest a key regulatory role for this microRNA in preventing lung fibrosis. Clinical trial registered with www.clinicaltrials.gov (NCT 00258544).
American Journal of Respiratory and Critical Care Medicine 07/2010; 182(2):220-9. · 11.08 Impact Factor
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American Journal of Respiratory and Critical Care Medicine 05/2010; 181(9):883-8. · 11.08 Impact Factor
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American Journal of Respiratory Cell and Molecular Biology 01/2010; 42(1):1-2. · 5.13 Impact Factor
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ABSTRACT: The transforming growth factor (TGF)-beta superfamily of secreted growth factors consists of more than 40 members, including the TGF-beta isoforms themselves, bone morphogenetic proteins, and activins. Most of these factors have been shown to be essential for proper organ development, a process often recapitulated in chronic diseases. Importantly, TGF-beta superfamily members are key regulators of extracellular matrix composition and alveolar epithelial cell and fibroblast function in the lung. Both during lung development and disease, TGF-betas therefore control lung homeostasis by providing the structural requirements and functional micromilieu needed for physiological epithelial cell function and proper gas exchange. Prolonged alterations of TGF-beta signaling have been shown to result in structural changes in the lung that compromise gas exchange and lung function, as seen in arrested lung development, a feature of bronchopulmonary dysplasia, lung fibrosis, and chronic obstructive pulmonary disease. All these syndromes share a loss of functional alveolar structures, which ultimately leads to a decreased life expectancy. In this review, we cover our current understanding of the impact of TGF-beta signaling on chronic lung disease. We focus on distorted TGF-beta signaling in bronchopulmonary dysplasia and chronic obstructive pulmonary disease as prototype diseases of the premature and matured lung, respectively, which are both characterized by functional and structural loss of alveolar units.
Proceedings of the American Thoracic Society 12/2009; 6(7):607-13.
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ABSTRACT: Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death in the developed world and associated with a high individual and socioeconomic burden. Despite emerging preventive efforts and ongoing clinical trials, the frequency and mortality of COPD are expected to continue to rise over the next decades. COPD is defined as an irreversible expiratory airflow limitation, which is caused by various degrees of the following two main features: First, small airway disease (SAD), which includes airway inflammation and remodelling, and second, emphysema, which is characterised by airspace enlargement. The major risk factor for COPD is cigarette smoke exposure; however, the molecular mechanisms linking smoke to different COPD features on the cellular level remain elusive. The transforming growth factor (TGF)-beta superfamily constitutes more than 40 members, which are essential during organ development, a process often recapitulated in chronic diseases. Emerging interest in the role of TGF-beta in the pathogenesis of COPD has recently evolved, particularly since genetic studies have demonstrated an association of gene polymorphisms of the TGF-beta superfamily with COPD. In addition, increased expression of TGF-beta1 in COPD lungs and primary cells, such as epithelial cells, macrophages, or fibroblasts isolated from COPD specimens, was reported, suggesting an impact of TGF-beta signalling on the development and progression of COPD. Thus, targeted interventions of TGF-beta signalling may represent a suitable therapeutic option in COPD. In this review, we will summarise the current understanding of the impact of TGF-beta in COPD pathogenesis. The review is separated into five chapters: 1) an introduction to COPD, 2) an introduction to TGF-beta signalling, 3) a summary of TGF-beta gene polymorphisms in COPD, 4) a summary of TGF-beta signalling in small airway disease, and 5) a summary of TGF-beta signalling in emphysema.
Swiss medical weekly: official journal of the Swiss Society of Infectious Diseases, the Swiss Society of Internal Medicine, the Swiss Society of Pneumology 10/2009; 139(39-40):554-63. · 1.89 Impact Factor
