Chronic obstructive pulmonary disease: role of matrix metalloproteases and future challenges of drug therapy

Tanimilast, A Novel Inhaled Pde4 Inhibitor for the Treatment of Asthma and Chronic Obstructive Pulmonary Disease

Chronic respiratory diseases are the third leading cause of death, behind cardiovascular diseases and cancer, affecting approximately 550 million of people all over the world. Most of the chronic respiratory diseases are attributable to asthma and chronic obstructive pulmonary disease (COPD) with this latter being the major cause of deaths. Despite differences in etiology and symptoms, a common feature of asthma and COPD is an underlying degree of airways inflammation. The nature and severity of this inflammation might differ between and within different respiratory conditions and pharmacological anti-inflammatory treatments are unlikely to be effective in all patients. A precision medicine approach is needed to selectively target patients to increase the chance of therapeutic success. Inhibitors of the phosphodiesterase 4 (PDE4) enzyme like the oral PDE4 inhibitor roflumilast have shown a potential to reduce inflammatory-mediated processes and the frequency of exacerbations in certain groups of COPD patients with a chronic bronchitis phenotype. However, roflumilast use is dampened by class related side effects as nausea, diarrhea, weight loss and abdominal pain, resulting in both substantial treatment discontinuation in clinical practice and withdrawal from clinical trials. This has prompted the search for PDE4 inhibitors to be given by inhalation to reduce the systemic exposure (and thus optimize the systemic safety) and maximize the therapeutic effect in the lung. Tanimilast (international non-proprietary name of CHF6001) is a novel highly potent and selective inhaled PDE4 inhibitor with proven anti-inflammatory properties in various inflammatory cells, including leukocytes derived from asthma and COPD patients, as well as in experimental rodent models of pulmonary inflammation. Inhaled tanimilast has reached phase III clinical development by showing promising pharmacodynamic results associated with a good tolerability and safety profile, with no evidence of PDE4 inhibitors class-related side effects. In this review we will discuss the main outcomes of preclinical and clinical studies conducted during tanimilast development, with particular emphasis on the characterization of the pharmacodynamic profile that led to the identification of target populations with increased therapeutic potential in inflammatory respiratory diseases.

Novel insights into the role of BRD4 in fine particulate matter induced airway hyperresponsiveness

Epidemiological research has identified that exposure to fine particulate matter (PM2.5) can increase airway hyperresponsiveness (AHR) which is considered a typical characteristic of asthma. Although the effect of PM2.5 on AHR has been elucidated to a certain degree, its exact mechanism remains unclear. Bromodomain-containing protein 4 (BRD4) is recognized as a member of the bromodomain and extraterminal (BET) family, with the ability to maintain higher-order chromatin configuration and regulate gene expression programs. The primary objective of our study was to examine the role of BRD4 in AHR triggered by PM2.5, and to elucidate its possible molecular mechanism. A mouse model with AHR was established using a nose-only PM2.5 exposure system. We observed that PM2.5 enhanced AHR in the experimental group compared to the control group, and this alteration was accompanied by increased lung inflammation and BRD4 expression in bronchi-lung tissue. However, the BRD4 inhibitor (ZL0420) could alleviate the aforementioned alterations in the mouse model with PM2.5 exposure. To explore the exact molecular mechanism, we further examined the role of BRD4 in human airway smooth muscle cells (hASMCs) after exposure to PM2.5 DMSO extracts. We found that PM2.5 DMSO extracts, which promoted the contraction and migration of hASMCs, was accompanied by an increase in the levels of BRD4, kallikrein 14 (KLK14), bradykinin 2 receptor (B2R), matrix metalloproteinases2(MMP-2), matrix metalloproteinases9(MMP-9), vimentin and bradykinin (BK) secretion, while ZL0420 and BRD4 gene silencing could reverse this response. In summary, these results demonstrate that BRD4 is an important player in AHR triggered by PM2.5, and BRD4 inhibition can ameliorate AHR induced by PM2.5. In addition, PM2.5 DMSO extracts can promote the contraction and migration of hASMCs by increasing BRD4 expression.

Longitudinal Imaging-Based Clusters in Former Smokers of the COPD Cohort Associate with Clinical Characteristics: The SubPopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS)

PURPOSE

Quantitative computed tomography (qCT) imaging-based cluster analysis identified clinically meaningful COPD former-smoker subgroups (clusters) based on cross-sectional data. We aimed to identify progression clusters for former smokers using longitudinal data.

PATIENTS AND METHODS

We selected 472 former smokers from SPIROMICS with a baseline visit and a one-year follow-up visit. A total of 150 qCT imaging-based variables, comprising 75 variables at baseline and their corresponding progression rates, were derived from the respective inspiration and expiration scans of the two visits. The COPD progression clusters identified were then associated with subject demography, clinical variables and biomarkers.

RESULTS

COPD severities at baseline increased with increasing cluster number. Cluster 1 patients were an obese subgroup with rapid progression of functional small airway disease percentage (fSAD%) and emphysema percentage (Emph%). Cluster 2 exhibited a decrease of fSAD% and Emph%, an increase of tissue fraction at total lung capacity and airway narrowing over one year. Cluster 3 showed rapid expansion of Emph% and an attenuation of fSAD%. Cluster 4 demonstrated severe emphysema and fSAD and significant structural alterations at baseline with rapid progression of fSAD% over one year. Subjects with different progression patterns in the same cross-sectional cluster were identified by longitudinal clustering.

CONCLUSION

qCT imaging-based metrics at two visits for former smokers allow for the derivation of four statistically stable clusters associated with unique progression patterns and clinical characteristics. Use of baseline variables and their progression rates enables identification of longitudinal clusters, resulting in a refinement of cross-sectional clusters.

Sputum and blood transcriptomics characterisation of the inhaled PDE4 inhibitor CHF6001 on top of triple therapy in patients with chronic bronchitis

Background

Although phosphodiesterase-4 (PDE4) inhibitors have been shown to reduce COPD exacerbation rate, their biological mechanism of action is not completely elucidated at the molecular level. We aimed to characterise the whole genome gene expression profile of the inhaled PDE4-inhibitor CHF6001 on top of triple therapy in sputum cells and whole blood of patients with COPD and chronic bronchitis.

Methods

Whole genome gene expression analysis was carried out by microarray in 54 patients before and after 32 days treatment with CHF6001 800 and 1600 μg and placebo twice daily (BID) in a randomised crossover study.

Results

CHF6001 had a strong effect in sputum, with 1471 and 2598 significantly differentially-expressed probe-sets relative to placebo (p-adjusted for False Discovery Rate < 0.05) with 800 and 1600 μg BID, respectively. Functional enrichment analysis showed significant modulation of key inflammatory pathways involved in cytokine activity, pathogen-associated-pattern-recognition activity, oxidative stress and vitamin D with associated inhibition of downstream inflammatory effectors. A large number of pro-inflammatory genes coding for cytokines and matrix-metalloproteinases were significantly differentially expressed for both doses; the majority (> 87%) were downregulated, including macrophage inflammatory protein-1-alpha and 1-beta, interleukin-27-beta, interleukin-12-beta, interleukin-32, tumour necrosis factor-alpha-induced-protein-8, ligand-superfamily-member-15, and matrix-metalloproteinases-7,12 and 14. The effect in blood was not significant.

Conclusions

Inhaled PDE4 inhibition by CHF6001 on top of triple therapy in patients with COPD and chronic bronchitis significantly modulated key inflammatory targets and pathways in the lung but not in blood. Mechanistically these findings support a targeted effect in the lung while minimising unwanted systemic class-effects.

Trial registration

ClinicalTrial.gov, EudraCT, 2015–005550-35. Registered 15 July 2016.

An Insight into COPD Morphopathogenesis: Chronic Inflammation, Remodeling, and Antimicrobial Defense

Background and Objectives: Intercellular signaling networks with high complexity cause a spectrum of mechanisms achieving chronic obstructive pulmonary disease (COPD) that still question many uncertainties. Materials and Methods: Immunoreactive cells in bronchial tissue obtained from 40 COPD patients and 49 healthy control subjects were detected by biotin-streptavidin immunohistochemistry method for the following markers of IL-1α, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, TNF-α, MMP-2, TIMP-2, TGF-β1, Hsp−70, hBD−2, hBD−3, hBD−4. Results: Overall the highest numbers (from mostly moderate (++) to abundance (++++)) of IL-1α, IL-4, IL-7, IL-8, IL-10, IL-12, MMP-2, TIMP-2, TGF-β1 immunoreactive cells were marked increasingly in the blood vessel wall, connective tissue, and bronchial epithelium of COPD-affected lung, respectively. We found statistically significant (p < 0.05) higher numbers of immunoreactive cells positive for all of examined interleukins, TNF-α, MMP-2, TIMP-2, TGF-β1, hBD-2, and hBD-3 in the COPD-affected lung compared to the control group, but not for Hsp-70 and hBD-4. Conclusions: COPD-affected lung tissue exhibits mostly inflammatory response patterns of increased IL-1α, IL-4, IL-8, IL-12, and TNF-α, especially in the airway epithelium. Increased MMP-2 and TGF-β1, but decreased Hsp-70, proposes pronounced tissue damage and remodeling in COPD. High numbers of hBD-2 and hBD-3 immunoreactive cells may highlight antimicrobial activity in COPD within stable regulation of local immunity.

The evaluation of inflammatory, anti-inflammatory and regulatory factors contributing to the pathogenesis of COPD in airways

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a progressive chronic disease leading to obstructive lung airways and airflow limitations. The background of COPD is extensive cytopathology and histopathology orchestrated by mostly chronic inflammation with the local release of inflammatory, anti-inflammatory and regulatory mediators, as well as further remodeling and shaping of local architecture. Inflammatory mechanisms are provided by complex intercellular signalling networks and regulation of locally occurring immune responses.

MATERIAL AND METHODS

In this study, lung tissue specimens obtained from 33 COPD patients and 49 control patients were analysed. Tissue samples were examined by hematoxylin and eosin staining. Immunoreactive cells positive for interleukin (IL)-1α (IL-1α), IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, and tumour necrosis factor-α (TNF-α) were detected by an immunohistochemistry (IHC) method.

RESULTS

We evaluated overall higher numbers of IL-7, IL-8 and IL-10 (mostly from few (0/+) to almost abundance (++++)) and overall less numbers of IL-1α and IL-6 (mostly from no positive (0) to numerous to abundance (+++/++++)) immunoreactive cells in airway epithelium and connective tissue of COPD affected lung. Furthermore, we evaluated statistically significant (P < 0.05) higher numbers of immunoreactive cells located in control group airway epithelium for IL-4, IL-6, IL-7, IL-10, and IL-12 compared to mucosal and submucosal connective tissue. Moreover, in COPD group airway epithelium for IL-1α, IL-4, IL-6, IL-7, IL-8, and IL-10. We found no statistically significant difference between the numbers of IL-12 and TNF-α immunoreactive cells in airway epithelium and connective tissue of COPD affected lung. In comparison with the control group, we found statistically significant (P < 0.05) higher numbers of immunoreactive cells positive for all examined markers in COPD group.

CONCLUSIONS

Increased numbers of IL-1α, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, and TNF-α immunoreactive cells highlight the local significance of these markers in COPD pathogenesis. Moreover, the pattern with dominance of immunoreactive cells in COPD affected airway epithelium over connective tissue is highlighting the essentials of epithelium in inflammatory signalling.

Matrix metalloproteinases in emphysema

Several studies have implicated a causative role for specific matrix metalloproteinases (MMPs) in the development and progression of cigarette smoke-induced chronic obstructive pulmonary disease (COPD) and its severe sequela, emphysema. However, the precise function of any given MMP in emphysema remains an unanswered question. Emphysema results from the degradation of alveolar elastin - among other possible mechanisms - a process that is often thought to be caused by elastolytic proteinases made by macrophages. In this article, we discuss the data suggesting, supporting, or refuting causative roles of macrophage-derived MMPs, with a focus on MMPs-7, -9, -10, -12, and 28, in both the human disease and mouse models of emphysema. Findings from experimental models suggest that some MMPs, such as MMP-12, may directly breakdown elastin, whereas others, particularly MMP-10 and MMP-28, promote the development of emphysema by influencing the proteolytic and inflammatory activities of macrophages.

The Isosteroid Alkaloid Imperialine from Bulbs of Fritillaria cirrhosa Mitigates Pulmonary Functional and Structural Impairment and Suppresses Inflammatory Response in a COPD-Like Rat Model

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death in the world. Present therapies for COPD have limited effect on reducing the progression of COPD and suppressing the inflammatory response in the lung. Bulbs of Fritillaria cirrhosa D. Don (BFC) have been used in many Asian countries for a long time to treat pulmonary diseases, such as cough, expectoration, and asthma. Steroidal alkaloids are the major biological active constituents in BFC, whereby imperialine is one of the important steroidal alkaloids. So far, there are no studies reporting the effect of imperialine on COPD. In this study, we investigated the effect of imperialine on pulmonary function and structure and inflammation in a COPD-like rat model which was induced by the combination of exposure to CS and intratracheal administration of LPS. Our data show that imperialine mitigates pulmonary functional and structural impairment and suppressed inflammatory response in a COPD-like rat model by mediating expression of related cytokines in lung tissues of the COPD-like rats, such as IL-1β, IL-6, IL-8, TNF-α, NF-κB, TGF-β1, MMP-9, and TIMP-1.

Interrelated role of cigarette smoking, oxidative stress, and immune response in COPD and corresponding treatments

Cigarette smoking (CS) can impact the immune system and induce pulmonary disorders such as chronic obstructive pulmonary disease (COPD), which is currently the fourth leading cause of chronic morbidity and mortality worldwide. Accordingly, the most significant risk factor associated with COPD is exposure to cigarette smoke. The purpose of the present study is to provide an updated overview of the literature regarding the effect of CS on the immune system and lungs, the mechanism of CS-induced COPD and oxidative stress, as well as the available and potential treatment options for CS-induced COPD. An extensive literature search was conducted on the PubMed/Medline databases to review current COPD treatment research, available in the English language, dating from 1976 to 2014. Studies have investigated the mechanism by which CS elicits detrimental effects on the immune system and pulmonary function through the use of human and animal subjects. A strong relationship among continued tobacco use, oxidative stress, and exacerbation of COPD symptoms is frequently observed in COPD subjects. In addition, therapeutic approaches emphasizing smoking cessation have been developed, incorporating counseling and nicotine replacement therapy. However, the inability to reverse COPD progression establishes the need for improved preventative and therapeutic strategies, such as a combination of intensive smoking cessation treatment and pharmaceutical therapy, focusing on immune homeostasis and redox balance. CS initiates a complex interplay between oxidative stress and the immune response in COPD. Therefore, multiple approaches such as smoking cessation, counseling, and pharmaceutical therapies targeting inflammation and oxidative stress are recommended for COPD treatment.

Inhalation of glycopyrronium inhibits cigarette smoke-induced acute lung inflammation in a murine model of COPD

Glycopyrronium bromide (GB) is a muscarinic receptor antagonist that has been used as a long-acting bronchodilator in chronic obstructive pulmonary disease (COPD) patients. The aim of this study was to investigate the anti-inflammatory activity of inhaled GB in a cigarette smoke-induced acute lung inflammation mouse model. We found that aerosol pre-treatment with GB suppresses the accumulation of neutrophils and macrophages in the bronchoalveolar lavage fluid (BALF) in cigarette smoke (CS)-exposed mice. GB at doses of 300 and 600 μg/ml significantly inhibited the CS-induced increases in the mRNA and protein expression levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, monocyte chemotactic protein (MCP)-1 and transforming growth factor (TGF)-β1 in lung tissues and the BALF. Moreover, GB at a dose of 600 μg/ml significantly inhibited the CS-induced changes in glutathione (GSH) and myeloperoxidase (MPO) activities in the BALF, decreased the CS-induced expression of matrix metalloproteinases (MMP)-9, and increased the CS-induced expression of tissue inhibitor of metalloproteinases (TIMP)-1, as determined through the immunohistochemical staining of lung tissue. Our results demonstrate the beneficial effects of inhaled GB on the inflammatory reaction in COPD.

The significance of matrix metalloproteinases in parasitic infections involving the central nervous system

Matrix metalloproteinases (MMPs) represent a large family of over twenty different secreted or membrane-bound endopeptidases, involved in many physiological (embryogenesis, precursor or stem cell mobilization, tissue remodeling during wound healing, etc.), as well as pathological (inflammation, tumor progression and metastasis in cancer, vascular pathology, etc.) conditions. For a long time, MMPs were considered only for the ability to degrade extracellular matrix (ECM) molecules (e.g., collagen, laminin, fibronectin) and to release hidden epitopes from the ECM. In the last few years, it has been fully elucidated that these molecules have many other functions, mainly related to the immune response, in consideration of their effects on cytokines, hormones and chemokines. Among others, MMP-2 and MMP-9 are endopeptidases of the MMP family produced by neutrophils, macrophages and monocytes. When infection is associated with leukocyte influx into specific organs, immunopathology and collateral tissue damage may occur. In this review, the involvement of MMPs and, in particular, of gelatinases in both protozoan and helminth infections will be described. In cerebral malaria, for example, MMPs play a role in the pathogenesis of such diseases. Also, trypanosomosis and toxoplasmosis will be considered for protozoan infections, as well as neurocysticercosis and angiostrongyloidosis, as regards helminthiases. All these situations have in common the proteolytic action on the blood brain barrier, mediated by MMPs.

Novel methods and strategies in the discovery of TACE inhibitors

INTRODUCTION

Tumor necrosis factor-α (TNF-α) is a key player in inflammation and joint damage in rheumatoid arthritis (RA). One treatment approach to exclude TNF-α from the biological system is by inhibiting tumor necrosis factor-alpha converting enzyme (TACE), the enzyme responsible for the production of its active form. To date, a number of TACE inhibitors have been reported in the literature from various strategies and methods.

AREAS COVERED

The following article presents the design and development strategies for the discovery of novel TACE inhibitors which could be of therapeutic utility for the alleviation of inflammatory conditions. The review is based on literature of the subject from 2005 onward.

EXPERT OPINION

Discovery of a selective TACE inhibitor has remained a major goal for many academic and pharmaceutical industrial research laboratories for quite some time. Identification of selective TACE inhibitors has proved elusive until recently due to structural similarities between TACE and MMPs. The differences in the shape and size of the S1' pocket of TACE and MMPs could be exploited to design selective TACE inhibitors devoid of any MMP inhibitory activity in the near future. It would be a Herculean task to develop a specific TACE inhibitor for clinical treatment of RA because binding subsites of TACE and MMPs are quite similar. However, developments taking place currently in the field as well as in the application of molecular modeling techniques at a wider scale could yet provide clinically useful selective TACE inhibitors in the not too distant future.

Classical and alternative macrophage activation in the lung following ozone-induced oxidative stress

Ozone is a pulmonary irritant known to cause oxidative stress, inflammation and tissue injury. Evidence suggests that macrophages play a role in the pathogenic response; however, their contribution depends on the mediators they encounter in the lung which dictate their function. In these studies we analyzed the effects of ozone-induced oxidative stress on the phenotype of alveolar macrophages (AM). Exposure of rats to ozone (2 ppm, 3h) resulted in increased expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG), as well as heme oxygenase-1 (HO-1) in AM. Whereas 8-OHdG was maximum at 24h, expression of HO-1 was biphasic increasing after 3h and 48-72 h. Cleaved caspase-9 and beclin-1, markers of apoptosis and autophagy, were also induced in AM 24h post-ozone. This was associated with increased bronchoalveolar lavage protein and cells, as well as matrix metalloproteinase (MMP)-2 and MMP-9, demonstrating alveolar epithelial injury. Ozone intoxication resulted in biphasic activation of the transcription factor, NFκB. This correlated with expression of monocyte chemotactic protein-1, inducible nitric oxide synthase and cyclooxygenase-2, markers of proinflammatory macrophages. Increases in arginase-1, Ym1 and galectin-3 positive anti-inflammatory/wound repair macrophages were also observed in the lung after ozone inhalation, beginning at 24h (arginase-1, Ym1), and persisting for 72 h (galectin-3). This was associated with increased expression of pro-surfactant protein-C, a marker of Type II cell proliferation and activation, important steps in wound repair. These data suggest that both proinflammatory/cytotoxic and anti-inflammatory/wound repair macrophages are activated early in the response to ozone-induced oxidative stress and tissue injury.

CCAAT/enhancer binding protein-α regulates the protease/antiprotease balance required for bronchiolar epithelium regeneration

Many transcription factors that regulate lung morphogenesis during development are reactivated to mediate repairs of the injured adult lung. We hypothesized that CCAAT/enhancer binding protein-α (C/EBPα), a transcription factor critical for perinatal lung maturation, regulates genes required for the normal repair of the bronchiolar epithelium after injury. Transgenic Cebpα(Δ/Δ) mice, in which Cebpa was conditionally deleted from Clara cells and Type II cells after birth, were used in this study. Airway injury was induced in mice by the intraperitoneal administration of naphthalene to ablate bronchiolar epithelial cells. Although the deletion of C/EBPα did not influence lung structure and function under unstressed conditions, C/EBPα was required for the normal repair of terminal bronchiolar epithelium after naphthalene injury. To identify cellular processes that are influenced by C/EBPα during repair, mRNA microarray was performed on terminal bronchiolar epithelial cells isolated by laser-capture microdissection. Normal repair of the terminal bronchiolar epithelium was highly associated with the mRNAs regulating antiprotease activities, and their induction required C/EBPα. The defective deposition of fibronectin in Cebpα(Δ/Δ) mice was associated with increased protease activity and delayed differentiation of FoxJ1-expressing ciliated cells. The fibronectin and ciliated cells were restored by the intratracheal treatment of Cebpα(Δ/Δ) mice with the serine protease inhibitor. In conclusion, C/EBPα regulates the expression of serine protease inhibitors that are required for the normal increase of fibronectin and the restoration of ciliated cells after injury. Treatment with serine protease inhibitor may aid in the recovery of injured bronchiolar epithelial cells, and prevent common chronic lung diseases.

Asthma and COPD - The C/EBP Connection

Asthma and chronic obstructive pulmonary disease (COPD) are the two most prominent chronic inflammatory lung diseases with increasing prevalence. Both diseases are associated with mild or severe remodeling of the airways. In this review, we postulate that the pathologies of asthma and COPD may result from inadequate responses and/or a deregulated balance of a group of cell differentiation regulating factors, the CCAAT/Enhancer Binding Proteins (C/EBPs). In addition, we will argue that the exposure to environmental factors, such as house dust mite and cigarette smoke, changes the response of C/EBPs and are different in diseased cells. These novel insights may lead to a better understanding of the etiology of the diseases and may provide new aspects for therapies.

Novel TACE inhibitors in drug discovery: a review of patented compounds

TNF-alpha converting enzyme (TACE), a pro-inflammatory cytokine, catalyzes the formation of TNF-alpha from membrane bound TNF-alpha precursor protein. TNF-alpha is believed to play pathophysiological roles in inflammation, anorexia, cachexia, septic shock, viral replication and so on. TNF-alpha is a key player in inflammation and joint damage in rheumatoid arthritis. While a variety of TACE inhibitors have been reported in the literature, a vast majority of these compounds are peptidic and peptide-like compounds that are expected to have bioavailability and pharmacokinetic problems, common to such compounds, limiting their clinical effectiveness. Low molecular mass, long acting, orally bioavailable inhibitors of TACE are, therefore, highly desirable for the treatment of potential chronic diseases mentioned above. A review of patented compounds as TACE inhibitors in drug discovery is given. A selection of interesting patents recorded from 2001 to 2009 is presented. Various novel TACE inhibitors developed by different companies have been discussed.

Current technological challenges in biomarker discovery and validation

In this review we will give an overview of the issues related to biomarker discovery studies with a focus on liquid chromatography-mass spectrometry (LC-MS) methods. Biomarker discovery is based on a close collaboration between clinicians, analytical scientists and chemometritians/statisticians. It is critical to define the final purpose of a biomarker or biomarker pattern at the onset of the study and to select case and control samples accordingly. This is followed by designing the experiment, starting with the sampling strategy, sample collection, storage and separation protocols, choice and validation of the quantitative profiling platform followed by data processing, statistical analysis and validation workflows. Biomarker candidates that result after statistical validation should be submitted for further validation and, ideally, be connected to the disease mechanism after their identification. Since most discovery studies work with a relatively small number of samples, it is necessary to assess the specificity and sensitivity of a given biomarker-based assay in a larger set of independent samples, preferably analyzed at another clinical center. Targeted analytical methods of higher throughput than the original discovery method are needed at this point and LC-tandem mass spectrometry is gaining acceptance in this field. Throughout this review, we will focus on possible sources of variance and how they can be assessed and reduced in order to avoid false positives and to reduce the number of false negatives in biomarker discovery research.

Design, synthesis, biological evaluation, and NMR studies of a new series of arylsulfones as selective and potent matrix metalloproteinase-12 inhibitors

Overexpression of macrophage elastase (MMP-12), a member of the matrix metalloproteinases family, can be linked to tissue remodeling and degradation in some inflammatory processes, such as chronic obstructive pulmonary disease (COPD), emphysema, rheumatoid arthritis (RA), and atherosclerosis. On this basis, MMP-12 can be considered an attractive target for studying selective inhibitors that are useful in the development of new therapies for COPD and other inflammatory diseases. We report herein the design, synthesis, and in vitro evaluation of a new series of compounds, possessing an arylsulfonyl scaffold, for their potential as selective inhibitors of MMP-12. The best compound in the series showed an IC50 value of 0.2 nM, with good selectivity over MMP-1 and MMP-14. A docking study was carried out on this compound in order to investigate its binding interactions with MMP-12, and NMR studies on the complex with the MMP-12 catalytic domain were able to validate the proposed binding mode.

Selective MMP-12 inhibitors: WO-2008057254

Amino-substituted xanthene, thioxanthene and carbazole sulfonamido-carboxylic acid of carboxamido carboxylic acid derivatives, their use to treat metalloprotease mediated conditions, and especially to inhibit MMP-12, and to treat osteoarthritis, rheumatoid arthritis, atherosclerosis, heart failure, fibrosis, pulmonary emphysema, tumour growth, asthma and chronic obstructive pulmonary disorder (COPD). Compounds of this category are suggested to be particularly useful in the treatment of COPD.

Association between matrix metalloproteinase-10 concentration and smoking in individuals without cardiovascular disease

INTRODUCTION AND OBJECTIVES

Smoking is an important cardiovascular risk factor whose underlying mechanism is incompletely understood. However, it has been suggested that alterations in the balance between synthesis and degradation of the extracellular matrix (ECM) may play a role. The aim of this study was to determine whether there is an independent association between smoking and the concentration of circulating metalloproteinases (MMPs) in individuals without cardiovascular disease.

METHODS

Metabolic parameters, the carotid intima-media thickness (IMT), inflammatory markers (fibrinogen, C-reactive protein and interleukin-6), markers of endothelial damage (e.g., von Willebrand factor), and the concentration of MMP-1, -9 and -10 and tissue inhibitor of metalloproteinase-1 (TIMP-1) were assessed in 400 asymptomatic individuals with cardiovascular risk factors. Subjects were divided into non-smokers (n=195), smokers (n=118) and former smokers (n=87). In addition, global cardiovascular risk was determined from PROCAM and REGICOR scores.

RESULTS

Both MMP-1 and MMP-10 concentrations were significantly higher in smokers than non-smokers (P< .05 and P< .001, respectively), though there was no difference in the levels of MMP-9, TIMP-1, IMT and other inflammatory parameters. There were positive correlations between the MMP-10 concentration and PROCAM and REGICOR scores (P< .001). Multivariate analysis showed that there was still an association between smoking and the MMP-10 concentration after adjustment for age, sex and other cardiovascular risk factors (P< .001). Multiple regression analysis showed that smoking accounted for 28% of the variability in the MMP-10 concentration.

CONCLUSIONS

There was an independent association between smoking and the MMP-10 concentration in asymptomatic individuals. This relationship between MMP-10 and the ECM may indicate a mechanism through which this MMP contributes to smoking-related atherosclerosis.

Salmeterol with fluticasone enhances the suppression of IL-8 release and increases the translocation of glucocorticoid receptor by human neutrophils stimulated with cigarette smoke

The combination of inhaled corticosteroids and long-acting beta2-adrenoceptor agonists is increasingly used in chronic obstructive pulmonary disease (COPD). Recently, we have demonstrated that combination of salmeterol and fluticasone propionate (FP) additionally suppress the production of IL-8 by human monocyte. In this study, the molecular mechanism behind the effectiveness of this combination therapy is investigated in human neutrophils. Human neutrophils were preincubated with salmeterol or FP or the combination. The amount of interleukin-8 (IL-8), elastase and matrix metalloproteinases (MMP)-2 and -9 releases, and reactive oxygen species (ROS) generation and expression of MAP kinase phosphatase (MKP-1) and glucocorticoid receptor (GR) were determined. Cigarette smoke medium (CSM) induces an increased expression of CXC receptors and the production of ROS that may explain the strong production of IL-8 by neutrophils. The expression of CXC receptors, the production of ROS, and the release of elastase and MMP-2 and -9 were not influenced by salmeterol, FP, or the combination. Interestingly, the combination therapy had an additive suppressive effect on the CSM-induced production of IL-8. The latter could be explained by an increased mRNA expression of MKP-1, the GR and an increased translocation of the GR to the nucleus. This leads eventually to suppression of both the NF-kappaB and MAPK pathways and, hence, to less IL-8 production by the neutrophil. These data are in support for the use of a combination therapy in COPD patients.