Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs in the respiratory tract: potential implications in asthma and other lung diseases

Alveolar macrophage activation and an emphysema-like phenotype in adiponectin-deficient mice

Adiponectin is an adipocyte-derived collectin that acts on a wide range of tissues including liver, brain, heart, and vascular endothelium. To date, little is known about the actions of adiponectin in the lung. Herein, we demonstrate that adiponectin is present in lung lining fluid and that adiponectin deficiency leads to increases in proinflammatory mediators and an emphysema-like phenotype in the mouse lung. Alveolar macrophages from adiponectin-deficient mice spontaneously display increased production of tumor necrosis factor-alpha (TNF-alpha) and matrix metalloproteinase (MMP-12) activity. Consistent with these observations, we found that pretreatment of alveolar macrophages with adiponectin leads to TNF-alpha and MMP-12 suppression. Together, our findings show that adiponectin leads to macrophage suppression in the lung and suggest that adiponectin-deficient states may contribute to the pathogenesis of inflammatory lung conditions such as emphysema.

Application of DNA microarray technology to influenza A/Vietnam/1194/2004 (H5N1) vaccine safety evaluation

We propose that DNA microarray analysis can be used in the quality control of pandemic and endemic influenza vaccine. Based on the expression profiles of 76 genes in the rat lung one day after inoculation of influenza vaccine, we can distinguish whole-virion influenza vaccine (PDv: pandemic influenza vaccine and WPv: whole virion-particle vaccine) and sub-virion vaccine (HA vaccine) from saline. Among these 76 genes, we found genes up-regulated by influenza infection, as well as genes involved in the immune response, and interferon. Hierarchical clustering of each influenza vaccine by the expression profiles of these 76 genes matched data from current quality control tests in Japan, such as the abnormal toxicity test (ATT) and the leukopenic toxicity test (LTT). Thus, it can be concluded that DNA microarray technology is an informative, rapid and highly sensitive method with which to evaluate the quality of influenza vaccines. Using DNA microarray system, consistent with the results of the ATT and LTT, it was clarified that there was no difference in vaccine quality between PDv and WPv.

Maternal betamethasone and chorioamnionitis induce different collagenases during lung maturation in fetal sheep

BACKGROUND

Fetal lung maturation occurs after both maternal corticosteroid administration and chorioamnionitis. The effectors of this antenatally-induced lung maturation are not understood. Matrix metalloproteinases (MMPs) 2 and 9 are type-IV collagenases that can degrade alveolar basement membranes.

OBJECTIVES

We hypothesized that the structural changes of lung maturation by both antenatal corticosteroid treatment and chorioamnionitis would be associated with increases in these MMPs.

METHODS

64 pregnant ewes were randomly assigned to one of four treatment groups: intra-amniotic injection of 10 mg endotoxin, maternal intramuscular injection of 0.5 mg/kg betamethasone, both treatments combined or saline-treated controls. We quantified MMP-2 which is derived from connective tissue and MMP-9 which is predominantly derived from neutrophils in fetal lung fluid of lambs after maternal corticosteroid therapy and induction of chorioamnionitis and the combination of both therapies given at 109-111 days' gestational age with delivery 1, 5 or 15 days later.

RESULTS

Betamethasone, endotoxin and the combined treatments increased both surfactant pool size, lung gas volume and reduced alveolar wall thickness at 15 days. MMP-2 concentration was increased after betamethasone. MMP-9 concentration increased after endotoxin-induced chorioamnionitis but decreased by the combined treatments.

CONCLUSION

Lung maturation via different pathways may use different forms of collagenases for remodelling lung structure.

Augmented epithelial endothelin-1 expression in refractory asthma

BACKGROUND

Airway remodeling in patients with severe steroid-refractory asthma might result from a reduced ability of steroid therapy to limit the transcription of remodeling factors by the bronchial epithelium.

OBJECTIVE

We sought to compare the levels of transcripts encoding remodeling factors in bronchial epithelium of healthy volunteers and of asthmatic patients with either steroid-sensitive or steroid-refractory disease and to correlate these levels with hallmarks of airway remodeling.

METHODS

By means of real-time quantitative PCR, we assessed the levels of 14 transcripts encoding remodeling factors, matrix metalloproteinases, and extracellular matrix proteins in laser-capture microdissected bronchial epithelium of healthy volunteers, patients with mild steroid-untreated asthma, and patients with steroid-sensitive and steroid-refractory asthma (n = 8-10 in each group). Histologic features of airway remodeling and endothelin-1 (EDN1) immunolocalization were determined by using frozen specimens.

RESULTS

Patients with steroid-refractory asthma had greater levels of EDN1 transcripts (4.1-fold increase, P = .026) and protein (P = .0009) in their bronchial epithelium compared with patients with steroid-sensitive asthma. EDN1 mRNA levels and protein expression in asthmatic patients were negatively correlated with prebronchodilator and postbronchodilator FEV(1) value (r(2) >or= 0.193, P <or= .03), and they were positively related to airway smooth muscle areas (r(2) = 0.253, P = .01 and r(2) = 0.281, P = .005 for EDN1 mRNA and protein expression, respectively).

CONCLUSION

Increased EDN1 synthesis by the bronchial epithelium characterizes severe refractory asthma and correlates with airway remodeling and airflow obstruction.

CLINICAL IMPLICATIONS

Targeting EDN1 might represent a novel therapeutic strategy for severe steroid-refractory asthma.

Fibrotic response as a distinguishing feature of resistance and susceptibility to pulmonary infection with Mycobacterium tuberculosis in mice

The differential susceptibility of inbred mouse strains DBA/2J (susceptible) and C57BL/6J (resistant) to pulmonary tuberculosis following aerosol infection is under complex genetic control. In this report, transcriptional profiling with RNAs from Mycobacterium tuberculosis-infected lungs was used to investigate the physiological response, cell type, and biochemical pathways underlying differential susceptibility to infection. Statistical analysis of cDNA-based microarrays revealed that 1,097 transcripts showed statistically significant changes in abundance (changes of > or = 1.5-fold) in at least one of four experimental group comparisons (C57BL/6J [day 0] versus DBA/2J [day 0] mice, C57BL/6J [day 90] versus DBA/2J [day 90] mice, C57BL/6J [day 90] versus C57BL/6J [day 0] mice, or DBA/2J [day 90] versus DBA/2J [day 0] mice). A group of genes showing very high degrees of significance (changes of > or = 2.0-fold) displayed enrichment for transcripts associated with tissue remodeling and the fibrotic response. The differential expression of fibrotic response genes (Sparc, Col1a1, Col1a2, Col4a1, and Col4a2) in the infected lungs of the two mouse strains was validated by another microarray platform (Affymetrix oligonucleotide chips) and by reverse transcription-PCR. Furthermore, the differential expression of additional genes known to be associated with fibrosis (Mmp2, Timp1, and Arg1) was also validated by these approaches. Overall, these results identify the differential fibrotic response as a pathological basis for the high susceptibility of DBA/2J mice to pulmonary tuberculosis.

Leukotriene D4 enhances the function of endothelin-1-primed fibroblasts

Airway inflammation is accompanied by structural changes, termed remodeling, that lead to lung dysfunction over the long term. Although both endothelin-1 (ET-1) and cysteinyl leukotrienes (CysLTs) appear to be involved in airway remodeling in several lung diseases, how these molecules interact remains largely unknown. In this study, we examined the effects of leukotriene (LT) D(4) on the function of ET-1-primed fibroblasts. ET-1 at 10(-7) M up-regulated the expression of the CysLT receptors at both the mRNA and protein levels in human lung fibroblasts. LTD(4) enhanced matrix metalloproteinase-2 and pro-collagen production, and alpha-smooth muscle actin expression of ET-1-primed fibroblasts, but had little or no effect on unprimed fibroblasts. The CysLT1 receptor antagonist montelukast completely abrogated the effects of LTD(4). Our data suggested that LTD(4) may act as a precipitating factor during ET-1-mediated airway remodeling and that CysLT1 receptor antagonists may have a role in preventing aberrant extracellular matrix degradation.

A novel formulation of inhaled doxycycline reduces allergen-induced inflammation, hyperresponsiveness and remodeling by matrix metalloproteinases and cytokines modulation in a mouse model of asthma

BACKGROUND

In this study, we assess the effectiveness of inhaled doxycycline, a tetracycline antibiotic displaying matrix metalloproteinases (MMP) inhibitory effects to prevent allergen-induced inflammation, hyperresponsiveness and remodeling. MMPs play key roles in the complex cascade of events leading to asthmatic phenotype.

METHODS

Doxycycline was administered by aerosols by the mean of a novel formulation as a complex with hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD) used as an excipient. BALB/c mice (n=16-24 in each group) were sensitized and exposed to aerosolized ovalbumin (OVA) from day 21 to 27 (short-term exposure protocol) or 5 days/odd weeks from day 22 to 96 (long-term exposure protocol).

RESULTS

In the short-term exposure model, inhaled doxycycline decreased allergen-induced eosinophilic inflammation in bronchoalveolar lavage (BAL) and in peribronchial areas, as well as airway hyperresponsiveness. In lung tissue, exposure to doxycycline via inhaled route induced a fourfold increase in IL-10 levels, a twofold decrease in IL-5, IL-13 levels and diminished MMP-related proteolysis and the proportion of activated MMP-9 as compared to placebo. In the long-term exposure model, inhaled doxycycline significantly decreased the extent of glandular hyperplasia, airway wall thickening, smooth muscle hyperplasia and subepithelial collagen deposition which are well recognized features of airway remodeling.

CONCLUSION

Doxycycline administered by aerosols decreases the allergen-induced airway inflammation and hyperresponsiveness and inhibits the development of bronchial remodeling in a mouse model of asthma by modulation of cytokines production and MMP activity.

Identification and Validation of Proteinase 3 and Latent Matrix-Metalloproteinase 9 as Potential Biomarkers for Chronic Lung Transplant Rejection

Introduction

This study examined potential biomarkers for the diagnosis and early detection of chronic allograft rejection after lung transplantation.

Methods

Protein ratios in pooled samples of bronchoalveolar lavage fluid (BALF) from lung transplant recipients at different stages of pre- and postchronic rejection were determined by iTRAQ labeling and mass spectrometry. The potential biomarkers were validated using enzyme-linked immunosorbent assay (ELISA) assay.

Results

Two hundred sixty-five proteins were identified, about two thirds of which showed more than a twofold difference between a pooled control sample (individuals who did not develop chronic rejection in 100 months) and a pooled sample from those with chronic rejection. Proteinase 3 (PR-3) and matrix metalloproteinase 9 (MMP-9) were validated by ELISA assay of 124 individual samples. PR-3 and the latent form of MMP-9 (proMMP9) both demonstrated a specificity of 92% with sensitivities of 76% and 82%, respectively, for disease diagnosis; both were also predictors of developing chronic rejection up to 15 months before diagnosis. While immunoglobulin M (IgM) was upregulated in the pooled samples, individual sample analysis revealed that this arose from outlier values.

Conclusions

iTRAQ can be used to detect a large number of proteins in pooled samples for the discovery of potential biomarkers, but the findings must be validated with technology capable of distinguishing broadly based changes from outcomes as a result of a few extreme cases. The proteins identified in this study expanded the panel of potential biomarkers for the diagnosis and prediction of chronic rejection and provided additional insight into the mechanism of the disease.

Elevated levels of plasma matrix metalloproteinase-9 in patients with atopic dermatitis: a pilot study

Matrix metalloproteinase (MMP)-9 has been shown to play a role in the infiltration of inflammatory cells in various tissues. It is thus part of the pathogenesis of many inflammatory diseases, including asthma and allergic rhinitis/conjunctivitis. We compared plasma MMP-9 levels of 20 patients with atopic dermatitis (AD) with that of 17 control subjects. Additional outcome parameters consisted of the modified objective SCORing Atopic Dermatitis and the Three Item Severity score in patients, and peripheral blood leucocytes and eosinophils in both groups. Plasma MMP-9 levels were found to be significantly higher in patients compared with controls, supporting a role for MMP-9 in the pathogenesis of AD.

Matrix metalloproteinase-2 protein in lung periphery is related to COPD progression

BACKGROUND

There is increasing evidence that matrix metalloproteinases (MMPs) may contribute to the pathogenesis of COPD, but their role in humans is not completely understood. We performed this study to quantify the expression of MMP-2 in a population of COPD patients at different stages of severity.

METHODS

We collected surgical specimens from 46 subjects, as follows: 10 smokers with severe COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage III-IV); 13 smokers with mild/moderate COPD (GOLD stage I-II); 12 control smokers; and 11 nonsmoking control subjects. We quantified MMP-2 expression in alveolar macrophages, alveolar walls, peripheral airways, and pulmonary arterioles by immunohistochemistry.

RESULTS

In all compartments, MMP-2 expression was increased both in smokers with severe COPD and in smokers with mild/moderate COPD compared to control smokers and nonsmokers (p < 0.05 for all comparisons). Only in alveolar macrophages was MMP-2 expression increased in smokers with severe COPD compared to smokers with mild/moderate COPD (p = c0.002). Moreover, MMP-2 expression was inversely related to values of FEV1/FVC ratio (p < 0.0001; r = -0.71) and Pao2 (in millimeters of Hg) [p = 0.005; r = -0.49], and was positively related to emphysema score (p = 0.01; r = 0.65) and residual volume percent predicted (p = 0.04; r = 0.49). A stepwise increase in the total number of alveolar macrophages was observed in the four groups of subjects examined, with the highest value in those with severe COPD.

CONCLUSION

This study shows that MMP-2 expression in the lung periphery progressively increases as lung function worsens and the degree of emphysema increases. These results suggest that MMP-2 may be a key mediator of the mechanisms leading to lung tissue remodeling and inflammation in patients with severe COPD.

Activation and localization of matrix metalloproteinase-2 and -9 in the skeletal muscle of the muscular dystrophy dog (CXMDJ)

Background

Matrix metalloproteinases (MMPs) are key regulatory molecules in the formation, remodeling and degradation of all extracellular matrix (ECM) components in both physiological and pathological processes in various tissues. The aim of this study was to examine the involvement of gelatinase MMP family members, MMP-2 and MMP-9, in dystrophin-deficient skeletal muscle. Towards this aim, we made use of the canine X-linked muscular dystrophy in Japan (CXMD_J) model, a suitable animal model for Duchenne muscular dystrophy.

Methods

We used surgically biopsied tibialis cranialis muscles of normal male dogs (n = 3) and CXMD_J dogs (n = 3) at 4, 5 and 6 months of age. Muscle sections were analyzed by conventional morphological methods and in situ zymography to identify the localization of MMP-2 and MMP-9. MMP-2 and MMP-9 activity was examined by gelatin zymography and the levels of the respective mRNAs in addition to those of regulatory molecules, including MT1-MMP, TIMP-1, TIMP-2, and RECK, were analyzed by semi-quantitative RT-PCR.

Results

In CXMD_J skeletal muscle, multiple foci of both degenerating and regenerating muscle fibers were associated with gelatinolytic MMP activity derived from MMP-2 and/or MMP-9. In CXMD_J muscle, MMP-9 immunoreactivity localized to degenerated fibers with inflammatory cells. Weak and disconnected immunoreactivity of basal lamina components was seen in MMP-9-immunoreactive necrotic fibers of CXMD_J muscle. Gelatinolytic MMP activity observed in the endomysium of groups of regenerating fibers in CXMD_J did not co-localize with MMP-9 immunoreactivity, suggesting that it was due to the presence of MMP-2. We observed increased activities of pro MMP-2, MMP-2 and pro MMP-9, and levels of the mRNAs encoding MMP-2, MMP-9 and the regulatory molecules, MT1-MMP, TIMP-1, TIMP-2, and RECK in the skeletal muscle of CXMD_J dogs compared to the levels observed in normal controls.

Conclusion

MMP-2 and MMP-9 are likely involved in the pathology of dystrophin-deficient skeletal muscle. MMP-9 may be involved predominantly in the inflammatory process during muscle degeneration. In contrast, MMP-2, which was activated in the endomysium of groups of regenerating fibers, may be associated with ECM remodeling during muscle regeneration and fiber growth.

Functional −1562 C-to-T polymorphism in matrix metalloproteinase-9 (MMP-9) promoter is associated with the risk for oral squamous cell carcinoma in younger male areca users

BACKGROUND

Circulating matrix metalloproteinase-9 (MMP-9) is a prognostic factor for gastric cancer and vascular diseases, and has been associated with head and neck cancers. The -1562 C-to-T polymorphism in MMP-9 promoter (abbreviated MMP-9 -1562 C>T polymorphism) leads to differential transcription, and is associated with increased susceptibility to neoplastic and vascular diseases. Thus, our aim was to determine whether a functional MMP-9 polymorphism might also influence the risk or affect the progression of areca-associated oral cancers.

METHODS

Genomic DNAs were obtained from peripheral blood cells of male subjects with areca-associated oral squamous cell carcinoma (OSCC) (n = 192), oral submucosal fibrosis (OSF) (n = 73), and non-diseased areca users (n = 191). The PCR-based restriction fragment length polymorphism analysis was performed for MMP-9 genotyping.

RESULTS

MMP-9 -1562 C>T polymorphism was not associated with the risk of OSCC or OSF. However, when subjects were stratified by the median age, an association with the risk of OSCC was found in younger patients (P = 0.029). The T allele frequency was significantly higher in the subset of older patients with buccal mucosa OSCC than older patients with OSCC in counterpart locations. The joint MMP-9 -1562 C>T and MMP-3 -1171 5A>6A functional polymorphisms were not associated with OSCC risk or patient survival.

CONCLUSION

Aberrant MMP-9 expression is closely related to tumor invasiveness and the prognosis of head and neck cancers. However, functional MMP-9 -1562 C>T polymorphism is associated with OSCC risk only in younger areca chewers. The impact of aging or areca-related effect on this functional polymorphism should be elucidated.

Metalloproteinase function in chronic rhinosinusitis with nasal polyposis

OBJECTIVES

Chronic rhinosinusitis with nasal polyposis (CRSwNP) and asthma share characteristic inflammatory features and histopathologic findings of airway remodeling. Remodeling, which is controlled by matrix metalloproteinases (MMP), is a key event in the pathogenesis of asthma. The MMP functions have rarely been evaluated in CRSwNP.

STUDY DESIGN

Prospective and in vivo.

METHODS

MMP-7, MMP-8, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-1 concentrations were analyzed by enzyme-linked immunosorbent assay and their molecular forms by Western immunoblotting and gelatin zymography in 24 patients operated on for CRSwNP and in nasal lavages from 19 healthy controls. MMP function, protective or destructive, was evaluated by comparing MMP/TIMP-1 levels with the disease activity, estimated by tissue eosinophilia and a need for re-operations.

RESULTS

Significantly increased levels of MMP-8/TIMP-1 and MMP-9/TIMP-1 were found in patients without tissue eosinophilia relative to eosinophil-positive CRSwNP patients and controls, as well as in patients who did not require re-operation in comparison with re-operated patients. In eosinophil-positive and re-operated patients, these parameters were within the same range than in controls.

CONCLUSIONS

Proteolytic spectrum is different in eosinophilic and noneosinophilic CRSwNP, suggesting a new mechanism for eosinophil accumulation in the disease pathogenesis. Enhanced MMP-8 and MMP-9 expression was associated with a better prognosis/clinical outcome, and thus these results may represent a synergic, protective role of MMP-8 and MMP-9 in host response in CRSwNP. Because synthetic MMP inhibitors, capable of equilibrating the unfavorable MMP/TIMP-ratio, may be of potential therapeutic value in chronic respiratory tract diseases, the MMP functions in inflammatory conditions need to be carefully established.

Inflammation after intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a devastating clinical event without effective therapies. Increasing evidence suggests that inflammatory mechanisms are involved in the progression of ICH-induced brain injury. Inflammation is mediated by cellular components, such as leukocytes and microglia, and molecular components, including prostaglandins, chemokines, cytokines, extracellular proteases, and reactive oxygen species. Better understanding of the role of the ICH-induced inflammatory response and its potential for modulation might have profound implications for patient treatment. In this review, a summary of the available literature on the inflammatory responses after ICH is presented along with discussion of some of the emerging opportunities for potential therapeutic strategies. In the near future, additional strategies that target inflammation could offer exciting new promise in the therapeutic approach to ICH.

DNA sequence variations of metalloproteinases: their role in asthma and COPD

Asthma and chronic obstructive pulmonary disease (COPD) are complex genetic diseases that cause considerable morbidity and mortality worldwide. Genetic variability interacting with environmental and ethnic factors is presumed to cause tobacco smoke susceptibility and to influence asthma severity. A disintegrin and metalloproteinase 33 (ADAM33) and matrix metalloproteinase-9 (MMP9) appear to have important roles in asthma and COPD pathogenesis. ADAM33 and MMP9 genetic alterations could possibly contribute to the establishment and progression of these multifactorial diseases, although their association with the clinical phenotypes has not yet been elucidated. However, the occurrence of these alterations does not always result in clear disease, implying that either they are an epiphenomenon or they are in proximity to the true causative alteration. This review summarises the most recent literature dealing with the genetic variations of metalloproteinases and outlines their potential pathogenetic outcome.

New Insights into the Pathogenesis and Treatment of Idiopathic Pulmonary Fibrosis: A Potential Role for Stem Cells in the Lung Parenchyma and Implications for Therapy

Idiopathic Pulmonary Fibrosis (IPF) is a chronic, progressive, and often fatal form of interstitial lung disease. It is characterized by injury with loss of lung epithelial cells and abnormal tissue repair, resulting in replacement of normal functional tissue, abnormal accumulation of fibroblasts and myofibroblasts, deposition of extracellular matrix, and distortion of lung architecture which results in respiratory failure. Despite improvements in the diagnostic approach to IPF and active research in recent years, the molecular mechanisms of the disease remain poorly understood. This highly lethal lung disorder continues to pose major clinical challenges since an effective therapeutic regimen has yet to be identified and developed. For example, a treatment modality has been based on the assumption that IPF is a chronic inflammatory disease, yet most available anti-inflammatory drugs are not effective in treating it. Hence researchers are now focusing on understanding alternative underlying mechanisms involved in the pathogenesis of IPF in the hope of discovering potentially new pharmaceutical targets. This paper will focus on lung tissue repair, regeneration, remodeling, and cell types that may be important to consider in therapeutic interventions and includes a more detailed discussion of the potential targets of current therapeutic attack in pulmonary fibrosis. The discovery that adult bone marrow stem cells can contribute to the formation of differentiated cell types in other tissues, especially after injury, implies that they have the potential to participate in tissue remodeling, and perhaps regeneration. The current promise of the use of adult stem cells for tissue regeneration, and the belief that once irreversibly damaged tissue could be restored to a normal functional capacity using stem cell-based therapy, suggests a novel approach for treatment of diverse chronic diseases. However this optimism is tempered by current evidence that the pathogenesis of pulmonary fibrosis may involve the recruitment of bone marrow-derived fibroblasts, which are the key contributors to the pathogenesis of this chronic progressive disorder. Nevertheless, stem cell-related therapies are widely viewed as promising treatment options for patients suffering from various types of pulmonary diseases. Gender mismatched bone marrow or lung transplant recipients serve as natural populations in which to study the role of bone marrow-derived stem cells in recovery from pulmonary diseases. Understanding the mechanism of recruitment of stem cells to sites of injury, and their involvement in tissue repair, regeneration, and remodeling may offer a novel therapeutic target for developing more effective treatments against this fatal disorder. This article reviews the new concepts in the pathogenesis, current and future treatment options of pulmonary fibrosis, and the recent advances regarding the roles of stem cells in lung tissue repair, regeneration, and remodeling.

Gene expression profiling in the early phases of DMD: a constant molecular signature characterizes DMD muscle from early postnatal life throughout disease progression

Genome-wide gene expression profiling of skeletal muscle from Duchenne muscular dystrophy (DMD) patients has been used to describe muscle tissue alterations in DMD children older than 5 years. By studying the expression profile of 19 patients younger than 2 years, we describe with high resolution the gene expression signature that characterizes DMD muscle during the initial or "presymptomatic" phase of the disease. We show that in the first 2 years of the disease, DMD muscle is already set to express a distinctive gene expression pattern considerably different from the one expressed by normal, age-matched muscle. This "dystrophic" molecular signature is characterized by a coordinate induction of genes involved in the inflammatory response, extracellular matrix (ECM) remodeling and muscle regeneration, and the reduced transcription of those involved in energy metabolism. Despite the lower degree of muscle dysfunction experienced, our younger patients showed abnormal expression of most of the genes reported as differentially expressed in more advanced stages of the disease. By analyzing our patients as a time series, we provide evidence that some genes, including members of three pathways involved in morphogenetic signaling-Wnt, Notch, and BMP-are progressively induced or repressed in the natural history of DMD.

Downstream target genes of the neuropeptide S-NPSR1 pathway

The neuropeptide S (NPS)-NPS receptor 1 (NPSR1) pathway has recently been implicated in the pathogenesis of asthma. The purpose of this study was to identify downstream gene targets regulated by NPSR1 upon NPS stimulation. A total of 104 genes were found significantly up-regulated and 42 down-regulated by microarray analysis 6 h after NPS administration. By Gene Ontology enrichment analysis, the categories 'cell proliferation', 'morphogenesis' and 'immune response' were among the most altered. A TMM microarray database comparison suggested a common co-regulated pathway, which includes JUN/FOS oncogene homologs, early growth response genes, nuclear receptor subfamily 4 members and dual specificity phosphatases. The expression of four up-regulated genes, matrix metallopeptidase 10 (MMP10), INHBA (activin A), interleukin 8 (IL8) and EPH receptor A2 (EPHA2), exhibited a significant NPS dose-response relationship as confirmed by quantitative reverse-transcriptase-PCR and for MMP10 by immunoassay. Immunohistochemical analyses revealed that MMP10 and TIMP metallopeptidase inhibitor 3 (TIMP3) were both strongly expressed in bronchial epithelium, and macrophages and eosinophils expressed MMP10 in asthmatic sputum samples. Because remodeling of airway epithelium is a feature of chronic asthma, the up-regulation of MMP10 and TIMP3 by NPS-NPSR1 signaling may be of relevance in the pathogenesis of asthma.