The role of matrix metalloproteinases (MMPs) in the pathophysiology of chronic obstructive pulmonary disease (COPD): a therapeutic role for inhibitors of MMPs?

Protocol for isolating extracellular vesicles from human or mouse airway macrophages for functional assays and in vivo or in vitro experimentation

Macrophages are key players in host defense and lung injury, and their crosstalk with other cells dictates the course of the inflammatory response and tissue remodeling. Here, we present a protocol for isolating extracellular vesicles (EVs) from human bronchoalveolar lavage fluid (BALF) and for generating EVs from primary human or murine alveolar macrophages following stimulation by cigarette smoke extract. Furthermore, we describe how to measure matrix metalloproteinase (MMP)-12 activity on macrophage-derived EVs using a Förster resonance energy transfer assay.

MAP2K1 dampens cigarette smoke-induced inflammation via suppression of type I interferon pathway activation

Chronic obstructive pulmonary disease (COPD), comprised of chronic bronchitis and emphysema, is a leading cause of morbidity and mortality worldwide. Mitogen-activated protein 2 kinase (MAP2K) pathway activation is present in COPD lung tissue and a genetic polymorphism in Map2k1 associates with FEV1 decline in COPD, suggesting it may contribute to disease pathogenesis. To test the functional contribution of Map2k1 in cigarette smoke (CS)-induced lung inflammation, we used a short-term CS exposure model in mice deficient in myeloid Map2k1 (LysmCre+Mek1fl) and wild-type mice (Mek1fl). Mice deficient in myeloid Map2k1 had enhanced CS-induced lung inflammation characterized by increased neutrophil recruitment, vascular leak, augmented expression of elastolytic matrix metalloproteinases, and increased type I interferon-stimulated gene expression. The augmented neutrophilic inflammatory response could be abrogated by IFNAR1 blockade. These findings indicate that myeloid Map2k1 regulates the immune response to CS via inhibition of the type I interferon pathway. Overall, these results suggest that Map2k1 is a critical determinant in modulating the severity of CS-induced lung inflammation and its expression is protective.NEW & NOTEWORTHY Activation of the mitogen-activated protein kinases (MAPK)-ERK1/2 pathway is present in COPD lung tissue compared with healthy lungs. Our study using mice deficient in myeloid Map2k1 reveals that Map2k1 is a critical determinant in modulating the severity of CS-induced lung inflammation via suppression of type I interferon responses, and its expression is protective.

Sodium butyrate (SB) ameliorated inflammation of COPD induced by cigarette smoke through activating the GPR43 to inhibit NF-κB/MAPKs signaling pathways

Cigarette smoke is recognized as a major trigger for individuals with chronic obstructive pulmonary disease (COPD), leading to an amplified inflammatory response. The onset and progression of COPD are affected by multiple environmental and genetic risk factors, such as inflammatory mechanisms, oxidative stress, and an imbalance between proteinase and antiprotease. As a result, conventional drug therapies often have limited effectiveness. This study aimed to investigate the anti-inflammatory effect of sodium butyrate (SB) in COPD and explore its molecular mechanism, thereby deepening our understanding of the potential application of SB in the treatment of COPD. In our study, we observed an increase in the mRNA and protein expressions of inflammatory factors interleukin-1beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), Matrix metallopeptidase 9 (MMP9) and MMP12 in both NR8383 cell and rat models of COPD. However, these expressions were significantly reduced after SB treatment. Meanwhile, SB treatment effectively decreased the phosphorylation levels of nuclear transcription factor-kappa B (NF-κB) p65, c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) and inhibited the nuclear translocation of these proteins in the COPD cells, leading to a reduction in the expression of various inflammatory cytokines. Additionally, SB also inhibited the expression level of the Nod-like receptor pyrin domain 3 (NLRP3) inflammasome, which consists of NLRP3, apoptosis-associated speck-like protein (ASC), and Caspase-1 in the cigeratte smoke extract (CSE)-stimulated cells. Our results showed that CSE down-regulated the mRNA levels of G-protein-coupled receptor 43 (GPR43) and GPR109A, while SB only up-regulated the expression of GPR43 and had no effect on GPR109A. Moreover, additional analysis demonstrated that the knockdown of GPR43 diminishes the anti-inflammatory effects of SB. It is evident that siRNA-mediated knockdown of GPR43 prevented the reduction in mRNA expression of IL-1β, IL-6, TNF-α, MMP9, and MMP12, as well as the expression of phosphorylated proteins NF-κB p65, JNK, and p38 MAPKs with SB treatment. These findings revealed a SB/GPR43 mediated pathway essential for attenuating pulmonary inflammatory responses in COPD, which may offer potential new treatments for COPD.

CD147 and MMPs as key factors in physiological and pathological processes

Cluster of differentiation 147 (CD147) or extracellular matrix metalloproteinase inducer (EMMPRIN) is a transmembrane glycoprotein that induces the synthesis of matrix metalloproteinases (MMPs). MMPs, as zinc-dependent proteases and versatile enzymes, play critical roles in the degradation of the extracellular matrix (ECM) components, cleaving of the receptors of cellular surfaces, signaling molecules, and other precursor proteins, which may lead to attenuation or activation of such targets. CD147 and MMPs play essential roles in physiological and pathological conditions and any disorder in the expression, synthesis, or function of CD147 and MMPs may be associated with various types of disease. In this review, we have focused on the roles of CD147 and MMPs in some major physiological and pathological processes.

Mmp12 Is Upregulated by in utero Second-Hand Smoke Exposures and Is a Key Factor Contributing to Aggravated Lung Responses in Adult Emphysema, Asthma, and Lung Cancer Mouse Models

Matrix metalloproteinase-12 (Mmp12) is upregulated by cigarette smoke (CS) and plays a critical role in extracellular matrix remodeling, a key mechanism involved in physiological repair processes, and in the pathogenesis of emphysema, asthma, and lung cancer. While cigarette smoking is associated with the development of chronic obstructive pulmonary diseases (COPD) and lung cancer, in utero exposures to CS and second-hand smoke (SHS) are associated with asthma development in the offspring. SHS is an indoor air pollutant that causes known adverse health effects; however, the mechanisms by which in utero SHS exposures predispose to adult lung diseases, including COPD, asthma, and lung cancer, are poorly understood. In this study, we tested the hypothesis that in utero SHS exposure aggravates adult-induced emphysema, asthma, and lung cancer.

Methods: Pregnant BALB/c mice were exposed from gestational days 6–19 to either 3 or 10mg/m³ of SHS or filtered air. At 10, 11, 16, or 17weeks of age, female offspring were treated with either saline for controls, elastase to induce emphysema, house-dust mite (HDM) to initiate asthma, or urethane to promote lung cancer. At sacrifice, specific disease-related lung responses including lung function, inflammation, gene, and protein expression were assessed.

Results: In the elastase-induced emphysema model, in utero SHS-exposed mice had significantly enlarged airspaces and up-regulated expression of Mmp12 (10.3-fold compared to air-elastase controls). In the HDM-induced asthma model, in utero exposures to SHS produced eosinophilic lung inflammation and potentiated Mmp12 gene expression (5.7-fold compared to air-HDM controls). In the lung cancer model, in utero exposures to SHS significantly increased the number of intrapulmonary metastases at 58weeks of age and up-regulated Mmp12 (9.3-fold compared to air-urethane controls). In all lung disease models, Mmp12 upregulation was supported at the protein level.

Conclusion: Our findings revealed that in utero SHS exposures exacerbate lung responses to adult-induced emphysema, asthma, and lung cancer. Our data show that MMP12 is up-regulated at the gene and protein levels in three distinct adult lung disease models following in utero SHS exposures, suggesting that MMP12 is central to in utero SHS-aggravated lung responses.

Protective effect of Palmijihwanghwan in a mouse model of cigarette smoke and lipopolysaccharide-induced chronic obstructive pulmonary disease

Background

Palmijihwanghwan (PJH) is a traditional medicine and eight constituents derived from PJH possess anti-inflammatory activities. However, the scientific evidence for its potential as a therapeutic agent for inflammatory lung disease has not yet been studied. In this study, we examined the protective effect of PJH in a mouse model of chronic obstructive pulmonary disease (COPD) induced by cigarette smoke (CS) with lipopolysaccharide (LPS).

Methods

Mice received CS exposure for 8 weeks and intranasal instillation of LPS on weeks 1, 3, 5 and 7. PJH (100 and 200 mg/kg) was administrated daily 1 h before CS treatment for the last 4 weeks.

Results

Compared with CS plus LPS-exposed mice, mice in the PJH-treated group showed significantly decreased inflammatory cells count and reduced inflammatory cytokines including interleukin-1 beta (IL-1β), IL-6 and tumor necrosis factor alpha (TNF-α) levels in broncho-alveolar lavage fluid (BALF) and lung tissue. PJH also suppressed the phosphorylation of nuclear factor kappa B (NF-κB) and extracellular signal-regulated kinase1/2 (ERK1/2) caused by CS plus LPS exposure. Furthermore, CS plus LPS induced increases in matrix metallopeptidase (MMP)-7, MMP-9, and transforming growth factor-β (TGF-β) expression and collagen deposition that were inhibited in PJH-treated mice.

Conclusions

This study demonstrates that PJH prevents respiratory inflammation and airway remodeling caused by CS with LPS exposure suggesting potential therapy for the treatment of COPD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03453-5.

Matrix Metalloproteinase MMP-12 Promotes Macrophage Transmigration Across Intestinal Epithelial Tight Junctions and Increases Severity of Experimental Colitis

BACKGROUND AND AIMS

Matrix metalloproteinases [MMPs] play an important role in extracellular matrix regulation during cell growth and wound healing. Increased expression of MMP-12 [human macrophage elastase] has been reported in inflammatory bowel disease [IBD] which is characterised by the loss of epithelial tight junction [TJ] barrier function and an excessive inflammatory response. The aim of this study was to investigate the role of MMP-12 in intestinal TJ barrier function and inflammation.

METHODS

Wild type [WT] and MMP-12-/- mice were subjected to experimental acute or chronic dextran sodium sulphate [DSS] colitis. The mouse colonic permeability was measured in vivo by recycling perfusion of the entire colon and ex vivo by Ussing chamber studies.

RESULTS

DSS administration increased colonic permeability through modulation of TJ proteins and also increased MMP-12 expression in the colonic mucosa of WT mice. The acute as well as chronic DSS-induced increase in colonic TJ permeability and the severity of DSS colitis was found to be markedly attenuated in MMP-12-/- mice. The resistance of MMP-12-/- mice to DSS colitis was characterised by reduced macrophage infiltration and transmigration, and reduced basement membrane laminin degradation. Further in vitro and in vivo studies show that macrophage transmigration across the epithelial layer is MMP-12 dependent and the epithelial TJ barrier is compromised during macrophage transmigration. Conclusions: Together, these data demonstrate that MMP-12 mediated degradation of basement membrane laminin, macrophage transmigration, and associated loss of intestinal TJ barrier are key pathogenic factors for intestinal inflammation.

Inhaled Corticosteroids and the Lung Microbiome in COPD

The Global Initiative for Chronic Obstructive Lung Disease 2021 Report recommends inhaled corticosteroid (ICS)-containing regimens as part of pharmacological treatment in patients with chronic obstructive lung disease (COPD) and frequent exacerbations, particularly with eosinophilic inflammation. However, real-world studies reveal overprescription of ICS in COPD, irrespective of disease presentation and inflammatory endotype, leading to increased risk of side effects, mainly respiratory infections. The optimal use of ICS in COPD therefore remains an area of intensive research, and additional biomarkers of benefit and risk are needed. Although the interplay between inflammation and infection in COPD is widely acknowledged, the role of the microbiome in shaping lower airway inflammation has only recently been explored. Next-generation sequencing has revealed that COPD disease progression and exacerbation frequency are associated with changes in the composition of the lung microbiome, and that the immunosuppressive effects of ICS can contribute to potentially deleterious airway microbiota changes by increasing bacterial load and the abundance of potentially pathogenic taxa such as Streptococcus and Haemophilus. Here, we explore the relationship between microbiome, inflammation, ICS use and disease phenotype. This relationship may inform the benefit:risk assessment of ICS use in patients with COPD and lead to more personalised pharmacological management.

Impact of long-term doxycycline on lung function & exacerbations: A real-world open, prospective pilot observation on chronic obstructive pulmonary disease

Background & objectives:

Upregulation of matrix metalloproteinases (MMPs) is related to the pathogenesis of chronic obstructive pulmonary disease (COPD). We aimed at assessing the tolerability and impact of long-term use of MMP inhibitor doxycycline in COPD.

Methods:

A cohort of COPD patients was randomized to continue a uniform COPD treatment with or without add-on long-term oral doxycycline. The lung exacerbations (spirometry), adverse events and health status (COPD Assessment Test score) were noted at 3, 6, 9 and 12 months of therapy. Measurement of the serum MMP-2, and 9 and high-sensitive C-reactive protein (hs-CRP) levels was done at the start of the study and at three months, whenever possible.

Results:

There were 27, 19, 13 and 10 patients with add-on doxycycline group and 22, 19, 11 and 7 patients with COPD treatment alone at 3, 6, 9 and 12 months of treatment respectively. The improvement was obviousaconsistent and serial improvement of health st nd mostly (at 6 and 12 months) significant (P>0.05) for lung function parameters [forced expiratory volume in one second (FEV₁), FEV₁/forced vital capacity (FVC) and forced expiratory flow at 25-75% of FVC (FEF_25-75)] and universal for health status at all measurements, with an overall 26.69 per cent reduction in exacerbations. The analysis with the lung function changes in the available population with protocol violation also supported the same trend. The concomitant reduction in serum MMP-9 (P=0.01), MMP-2 (P=0.01) and hs-CRP (P=0.0001) levels (n=21) at three months was also significant. The adverse reactions with add-on doxycycline appeared acceptable.

Interpretation & conclusions:

Long-term doxycycline appears well tolerated and seems to improve lung function, health status and exacerbations in COPD. The claim needs further scientific validations.

Revisiting matrix metalloproteinase 12: its role in pathophysiology of asthma and related pulmonary diseases

PURPOSE OF REVIEW

Matrix metalloproteinases (MMPs) are a family of over 20 zinc-dependent proteases with different biological and pathological activities, and many have been implicated in several diseases. Although nonselective MMP inhibitors are known to induce serious side-effects, targeting individual MMPs may offer a safer therapeutic potential for several diseases. Hence, we provide a concise overview on MMP-12, given its association with pulmonary diseases, including asthma, chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, and other progressive pulmonary fibrosis (PPF), which may also occur in coronavirus disease 2019.

RECENT FINDINGS

In asthma, COPD, and PPF, increased MMP-12 levels have been associated with inflammation and/or structural changes within the lungs and negatively correlated with functional parameters. Increased pulmonary MMP-12 levels and MMP-12 gene expression have been related to disease severity in asthma and COPD. Targeting MMP-12 showed potential in animal models of pulmonary diseases but human data are still very scarce.

SUMMARY

Although there may be a potential role of MMP-12 in asthma, COPD and PPF, several pathophysiological aspects await elucidation. Targeting MMP-12 may provide further insights into MMP-12 related mechanisms and how this translates into clinical outcomes; this warrants further research.

Serum levels of soluble Fas and Fas ligand in pregnant women who smoke

PROBLEM

Cigarette smoking during pregnancy is associated with reduced incidence of preeclampsia. Mechanisms of this association are poorly understood. Cytokines, angiogenic, and anti-angiogenic factors are involved in the pathogenesis of preeclampsia. During normal pregnancy, Fas ligand (FasL) present on trophoblasts induces apoptosis of Fas bearing maternal immune cells. In preeclampsia, trophoblasts show increased apoptosis with reduced expression of FasL. We determined serum levels of cytokines, angiogenic (placental growth factor), anti-angiogenic factors (soluble endoglin, soluble fms-like tyrosine kinase-1), soluble Fas (sFas), and soluble FasL (sFasL) in smoking and non-smoking pregnant women.

METHODS

Using enzyme-linked immunosorbent and multiplex assays, we prospectively analyzed serum levels of angiogenic, anti-angiogenic factors, cytokines, sFas and sFasL in normotensive smoking and non-smoking mothers. Exclusion criteria included maternal hypertension, auto-immune disorders, rupture of membranes, evidence of labor, and drug use.

RESULTS

Of 100 women recruited to the study, 51 were in the non-smoking and 49 in the smoking group. Except for lower maternal age in the smoking group, there was no difference in gestation, BMI, gravidity, or ethnicity between the two groups. Levels of angiogenic, anti-angiogenic factors, cytokines, and sFas were similar between the two groups but sFasL levels were significantly higher in smoking group (38 pg/ml vs. 16 pg/ml, p < .001) and remained significant after controlling for confounders.

CONCLUSION

Our study demonstrates higher sFasL levels in pregnant women who smoke. Higher sFasL may explain the reduced incidence of preeclampsia in pregnant mothers who smoke by inducing apoptosis of immune cells which may otherwise induce trophoblast apoptosis.

Neurturin regulates the lung-resident macrophage inflammatory response to viral infection

The neurotrophic factor RET is induced in lung macrophages by viral triggers and activation via its ligand neurturin regulates matrix proteins and cytokines that shape the inflammatory response.

Lung-resident macrophages are crucial to the maintenance of health and in the defence against lower respiratory tract infections. Macrophages adapt to local environmental cues that drive their appropriate function; however, this is often dysregulated in many inflammatory lung pathologies. In mucosal tissues, neuro-immune interactions enable quick and efficient inflammatory responses to pathogenic threats. Although a number of factors that influence the antimicrobial response of lung macrophages are known, the role of neuronal factors is less well understood. Here, we show an intricate circuit involving the neurotrophic factor, neurturin (NRTN) on human lung macrophages that dampens pro-inflammatory cytokine release and modulates the type of matrix metalloproteinases produced in response to viral stimuli. This circuit involves type 1 interferon–induced up-regulation of RET that when combined with the glial cell line-derived neurotrophic factor (GDNF) receptor α2 (GFRα2) allows binding to epithelial-derived NRTN. Our research highlights a non-neuronal immunomodulatory role for NRTN and a novel process leading to a specific antimicrobial immune response by human lung-resident macrophages.

Endothelial HIF-2α as a Key Endogenous Mediator Preventing Emphysema

Rationale: Endothelial injury may provoke emphysema, but molecular pathways of disease development require further discernment. Emphysematous lungs exhibit decreased expression of HIF-2α (hypoxia-inducible factor-2α)-regulated genes, and tobacco smoke decreases pulmonary HIF-2α concentrations. These findings suggest that decreased HIF-2α expression is important in the development of emphysema.Objectives: The objective of this study was to evaluate the roles of endothelial-cell (EC) HIF-2α in the pathogenesis of emphysema in mice.Methods: Mouse lungs were examined for emphysema after either the loss or the overexpression of EC Hif-2α. In addition, SU5416, a VEGFR2 inhibitor, was used to induce emphysema. Lungs were evaluated for HGF (hepatocyte growth factor), a protein involved in alveolar development and homeostasis. Lungs from patients with emphysema were measured for endothelial HIF-2α expression.Measurements and Main Results: EC Hif-2α deletion resulted in emphysema in association with fewer ECs and pericytes. After SU5416 exposure, EC Hif-2α-knockout mice developed more severe emphysema, whereas EC Hif-2α-overexpressing mice were protected. EC Hif-2α-knockout mice demonstrated lower levels of HGF. Human emphysema lung samples exhibited reduced EC HIF-2α expression.Conclusions: Here, we demonstrate a unique protective role for pulmonary endothelial HIF-2α and how decreased expression of this endogenous factor causes emphysema; its pivotal protective function is suggested by its ability to overcome VEGF antagonism. HIF-2α may maintain alveolar architecture by promoting vascular survival and associated HGF production. In summary, HIF-2α may be a key endogenous factor that prevents the development of emphysema, and its upregulation has the potential to foster lung health in at-risk patients.

Chemerin: A Potential Regulator of Inflammation and Metabolism for Chronic Obstructive Pulmonary Disease and Pulmonary Rehabilitation

Chronic obstructive pulmonary disease (COPD) features chronic inflammatory reactions of both intra- and extrapulmonary nature. Moreover, COPD is associated with abnormal glucose and lipid metabolism in patients, which influences the prognosis and chronicity of this disease. Abnormal glucose and lipid metabolism are also closely related to inflammation processes. Further insights into the interactions of inflammation and glucose and lipid metabolism might therefore inspire novel therapeutic interventions to promote lung rehabilitation. Chemerin, as a recently discovered adipokine, has been shown to play a role in inflammatory response and glucose and lipid metabolism in many diseases (including COPD). Chemerin recruits inflammatory cells to sites of inflammation during the early stages of COPD, leading to endothelial barrier dysfunction, early vascular remodeling, and angiogenesis. Moreover, it supports the recruitment of antigen-presenting cells that guide immune cells as part of the body's inflammatory responses. Chemerin also regulates metabolism via activation of its cognate receptors. Glucose homeostasis is affected via effects on insulin secretion and sensitivity, and lipid metabolism is changed by increased transformation of preadipocytes to mature adipocytes through chemerin-binding receptors. Controlling chemerin signaling may be a promising approach to improve various aspects of COPD-related dysfunction. Importantly, several studies indicate that chemerin expression in vivo is influenced by exercise. Although available evidence is still limited, therapeutic alterations of chemerin activity may be a promising target of therapeutic approaches aimed at the rehabilitation of COPD patients based on exercises. In conclusion, chemerin plays an essential role in COPD, especially in the inflammatory responses and metabolism, and has a potential to become a target for, and a biomarker of, curative mechanisms underlying exercise-mediated lung rehabilitation.

Effect of doxycyline in chronic obstructive pulmonary disease - An exploratory study

PURPOSE

Various mechanisms, including oxidative stress, inflammation, and protease-antiprotease imbalance are proposed for the progressive decline in lung function in chronic obstructive pulmonary disease (COPD). Doxycycline, a broad spectrum tetracycline antibiotic, is reported to have non-antimicrobial matrix metalloproteinases (MMP) inhibitory action in various inflammatory conditions. The effect of doxycycline in COPD is hereby assessed in the present randomized prospective study.

PATIENTS AND METHODS

The first group of COPD patients (n = 30; mild (n = 3), moderate (n = 6), severe (n = 7), very severe (n = 14) as per GOLD II & III criteria was prescribed the standard therapy, a combination of (i) short acting anti-muscarinic agent (SAMA) + short acting β2 agonist (SABA) inhaled and (ii) corticosteroid inhaled (ICS) + long acting β2 agonist (LABA) (iii) ICS + LABA + LAMA. Whereas doxycycline (100 mg), was used daily once or twice as per Body Mass Index (BMI), as an add-on to existing standard therapy for the second group of patients (n = 30; mild (n = 2), moderate (n = 7), severe (n = 8), very severe (n = 13). All recruited patients were followed-up after 3 months of treatment. Lung function index FEV1(%) predicted, FEV1/FVC (%), quality of life status including COPD Assessment Test (CAT), St. George's Respiratory Questionnaire (SGRQ) were assessed. Routine blood cell count also was performed.

RESULTS

Biochemical analysis included estimation of oxidative stress markers, inflammatory cytokines and proteases in plasma of both the groups. Reduction in oxidative stress is evidenced by a significant decrease in Lipid hydro peroxides (LPO), total oxidative stress (TOS) and increase in glutathione peroxidase (GSH-PX), reduced glutathione (GSH) and total anti-oxidant capacity (TAO) nitrite and nitrate (NOx) along with peroxynitrate following 3 months of add-on doxycycline treatment. Reduced levels of cytokines such as interleukin IL-6, TNF-α, IL-8 were also observed. Multivariate analysis identified TNF-α major effective discriminant among pre and post doxycycline treated COPD patients. The expression of TNF-α was inversely correlated with FEV1/FVC (%) changes. The levels of MMP-2 and MMP-9/tissue inhibitors of metalloproteinases (TIMP)-1 ratio (MMP-9/ TIMP-1), also decreased significantly and the decline could be associated with TOS. A significant increase in bilirubin and reduced glutathione (GSH) level was noticed in standard therapy group.

CONCLUSION

These data suggest that the improvement in lung function and quality of life in COPD patients may probably be attributed to the antioxidant, anti-inflammatory and anti-MMP activity of doxycycline. The potential therapeutic role of long-term doxycycline, in addition to its traditional antibiotic effect, definitely warrants further attention.

A randomized, triple-blind, placebo-controlled clinical trial, evaluating the sesamin supplement effects on proteolytic enzymes, inflammatory markers, and clinical indices in women with rheumatoid arthritis

Inflammation is one of the main characteristics of rheumatoid arthritis. Based on the antiinflammatory properties of sesame, this study was conducted to evaluate the sesamin supplement effects on serum levels of some proteolytic enzymes, inflammatory biomarkers, and clinical indices in women with rheumatoid arthritis. In this randomized, triple-blind, placebo-controlled clinical trial, 44 patients were randomly divided in intervention and control groups. Patients received 200-mg/day sesamin supplement or placebo in the intervention and control group for 6 weeks. Serum levels of proteolytic enzymes (hyaluronidase, aggrecanase, and matrix metalloproteinases-3) and inflammatory biomarkers (hs-CRP, IL-1β, IL-6, TNF-α, and cyclooxygenase-2) were measured with enzyme-linked immunosorbent assay method at the beginning and end of the study. After intervention, serum levels of hyaluronidase and matrix metalloproteinases-3 decreased significantly in sesamin group. Also, serum levels of hs-CRP, TNF-α, and cyclooxygenase-2 in intervention group were significantly decreased in intervention group compared with placebo group. Sesamin supplementation also caused a significant reduction in the number of tender joints and severity of pain in these patients. According to the results, it seems that the sesamin by reducing inflammatory mediators can relieve clinical symptoms and pathological changes that caused by inflammatory impairment in patients with rheumatoid arthritis.

Derepression of matrix metalloproteinase gene transcription and an emphysema-like phenotype in transcription factor Zbtb7c knockout mouse lungs

Dysregulated matrix metalloproteinase (MMP) gene expression is a major cause of the degradation of lung tissue that is integral to emphysema pathogenesis. Cigarette smoking (CS) increases MMP gene expression, a major contributor to emphysema development. We previously reported that Zbtb7c is a transcriptional repressor of several Mmp genes (Mmps-8, -10, -13, and -16). Here, we show that Zbtb7c knockout mice have mild emphysema-like phenotypes, including alveolar wall destruction, enlarged alveoli, and upregulated Mmp genes. Alveolar size and Mmp gene expression in Zbtb7c^-/- mouse lungs are increased more severely upon exposure to CS, compared to those of Zbtb7c^+/+ mouse lungs. These observations suggest that Zbtb7c degradation or absence may contribute to the pathogenesis of emphysema.

The etiologic origins for chronic obstructive pulmonary disease

COPD, characterized by long-term poorly irreversible airway limitation and persistent respiratory symptoms, has resulted in enormous challenges to human health worldwide, with increasing rates of prevalence, death, and disability. Although its origin was thought to be in the interactions of genetic with environmental factors, the effects of environmental factors on the disease during different life stages remain little known. Without clear mechanisms and radical cure for it, early screening and prevention of COPD seem to be important. In this review, we will discuss the etiologic origins for poor lung function and COPD caused by specific adverse effects during corresponding life stages, as well as try to find new insights and potential prevention strategies for this disease.

Accelerated 19F·MRI Detection of Matrix Metalloproteinase-2/-9 through Responsive Deactivation of Paramagnetic Relaxation Enhancement

Paramagnetic gadolinium ions (Gd^III), complexed within DOTA-based chelates, have become useful tools to increase the magnetic resonance imaging (MRI) contrast in tissues of interest. Recently, "on/off" probes serving as ¹⁹F·MRI biosensors for target enzymes have emerged that utilize the increase in transverse (T ₂ ^∗ or T ₂) relaxation times upon cleavage of the paramagnetic Gd^III centre. Molecular ¹⁹F·MRI has the advantage of high specificity due to the lack of background signal but suffers from low signal intensity that leads to low spatial resolution and long recording times. In this work, an "on/off" probe concept is introduced that utilizes responsive deactivation of paramagnetic relaxation enhancement (PRE) to generate ¹⁹F longitudinal (T ₁) relaxation contrast for accelerated molecular MRI. The probe concept is applied to matrix metalloproteinases (MMPs), a class of enzymes linked with many inflammatory diseases and cancer that modify bioactive extracellular substrates. The presence of these biomarkers in extracellular space makes MMPs an accessible target for responsive PRE deactivation probes. Responsive PRE deactivation in a ¹⁹F biosensor probe, selective for MMP-2 and MMP-9, is shown to enable molecular MRI contrast at significantly reduced experimental times compared to previous methods. PRE deactivation was caused by MMP through cleavage of a protease substrate that served as a linker between the fluorine-containing moiety and a paramagnetic Gd^III-bound DOTA complex. Ultrashort echo time (UTE) MRI and, alternatively, short echo times in standard gradient echo (GE) MRI were employed to cope with the fast ¹⁹F transverse relaxation of the PRE active probe in its "on-state." Upon responsive PRE deactivation, the ¹⁹F·MRI signal from the "off-state" probe diminished, thereby indicating the presence of the target enzyme through the associated negative MRI contrast. Null point ¹H·MRI, obtainable within a short time course, was employed to identify false-positive ¹⁹F·MRI responses caused by dilution of the contrast agent.

Targeted Treatments for Chronic Obstructive Pulmonary Disease (COPD) Using Low-Molecular-Weight Drugs (LMWDs)

Chronic obstructive pulmonary disease (COPD) is a very common and frequently fatal airway disease. Current therapies for COPD depend mainly on long-acting bronchodilators, which cannot target the pathogenic mechanisms of chronic inflammation in COPD. New pharmaceutical therapies for the inflammatory processes of COPD are urgently needed. Several anti-inflammatory targets have been identified based on increased understanding of the pathogenesis of COPD, which raises new hopes for targeted treatment of this fatal respiratory disease. In this review, we discuss the recent advances in bioactive low-molecular-weight drugs (LMWDs) for the treatment of COPD and, in addition to the first-line drug bronchodilators, focus particularly on low-molecular-weight anti-inflammatory agents, including modulators of inflammatory mediators, inflammasome inhibitors, protease inhibitors, antioxidants, PDE4 inhibitors, kinase inhibitors, and other agents. We also provide new insights into targeted COPD treatments using LMWDs, particularly small-molecule agents.

Chronic Cigarette Smoke Exposure Subdues PP2A Activity by Enhancing Expression of the Oncogene CIP2A

Phosphatase activity of the major serine threonine phosphatase, protein phosphatase 2A (PP2A), is blunted in the airways of individuals with chronic obstructive pulmonary disease (COPD), which results in heightened inflammation and proteolytic responses. The objective of this study was to investigate how PP2A activity is modulated in COPD airways. PP2A activity and endogenous inhibitors of PP2A were investigated in animal and cell models of COPD. In primary human bronchial epithelial (HBE) cells isolated from smokers and donors with COPD, we observed enhanced expression of cancerous inhibitor of PP2A (CIP2A), an oncoprotein encoded by the KIAA1524 gene, compared with cells from nonsmokers. CIP2A expression was induced by chronic cigarette smoke exposure in mice that coincided with a reduction in PP2A activity, airspace enlargements, and loss of lung function, as determined by PP2A phosphatase activity, mean linear intercept analysis, and forced expiratory volume in 0.05 second/forced vital capacity. Modulating CIP2A expression in HBE cells by silencing RNA or chemically with erlotinib enhanced PP2A activity, reduced extracellular-signal-regulated kinase phosphorylation, and reduced the responses of matrix metalloproteinases 1 and 9 in HBE cells isolated from subjects with COPD. Enhanced epithelial growth factor receptor responses in cells from subjects with COPD were observed to modulate CIP2A expression levels. Our study indicates that chronic cigarette smoke induction of epithelial growth factor receptor signaling and CIP2A expression can impair PP2A responses that are associated with loss of lung function and enhancement of proteolytic responses. Augmenting PP2A activity by manipulating CIP2A expression may represent a feasible therapeutic approach to counter smoke-induced lung disease.

Protective Effects of Nintedanib against Polyhexamethylene Guanidine Phosphate-Induced Lung Fibrosis in Mice

Nintedanib (NDN), a tyrosine kinase inhibitor, has been shown to have anti-tumor, anti-inflammatory, and anti-fibrotic effects in several reports. We investigated the protective effects of NDN against polyhexamethylene guanidine phosphate (PHMG)-induced lung fibrosis in mice. The following three experimental groups were evaluated: (1) vehicle control; (2) PHMG (1.1 mg/kg); and (3) PHMG & NDN (60 mg/kg). PHMG induced pulmonary inflammation and fibrosis by intratracheal instillation in mice. In contrast, NDN treatment effectively alleviated the PHMG induced lung injury, and attenuated the number of total cells and inflammatory cells in the bronchoalveolar lavage fluid, including the fibrotic histopathological changes, and also reduced the hydroxyproline content. NDN also significantly decreased the expression of inflammatory cytokines and fibrotic factors, and the activation of the NLRP3 inflammasome in lung tissues. These results suggest that NDN may mitigate the inflammatory response and development of pulmonary fibrosis in the lungs of mice treated with PHMG.

The effect of conjugated linoleic acid on oxidative stress and matrix metalloproteinases 2 and 9 in patients with COPD

Background

Natural antioxidants in foods may be used in prevention and treatment of oxidative stress and inflammation in COPD. Therefore, this study aimed to evaluate the effect of conjugated linoleic acid (CLA) supplement as natural antioxidants on oxidative stress levels, and MMP2 and MMP9 serum levels in COPD patients.

Materials and methods

This clinical trial study was conducted on 90 (supplement group=45 and control group=45) COPD patients in Ardabil city, Iran, in 2015. After obtaining written consent, general information was collected from each patient using a validated and reliable questionnaire. Supplement group received 3.2 g of CLA and those in the control group were given 3.2 g of placebo for 6 weeks on a daily basis. Fasting blood samples were taken from all of the patients for testing of malondialdehyde (MDA), MMP2, and MMP9 levels at the beginning and end of the study. Data were analyzed using Kolmogorov–Smirnov test, independent samples t-test, paired sample t-test, chi-square test, and ANOVA.

Results

There were no significant differences between the two groups with regard to mean age, smoking status, and serum level of MDA at the beginning of the study. In the supplement group, the serum level of MDA decreased significantly at the end of the 6th week compared to that in the beginning of the study (p=0.0004), while in the placebo group, the difference was found to be insignificant. The serum level of MMP9 decreased significantly in the supplement group, while in the placebo group its level increased significantly as compared to that at the beginning of the study (p<0.05). The serum levels of MMP2 indicated no significant differences between the two groups neither at the beginning nor at the end of the study.

Conclusion

These findings indicated that CLA supplementation may be helpful for COPD patients through inhibiting the production of oxidative stress and controlling MMP9 serum levels.

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.

Functional analysis implicating the SNP rs61552325 in ERBB2 as an effector for androgen-insensitive prostate cancer cell invasion

Background

As one of the most common cancers in men, the pathogenesis of prostate cancer has been widely researched. Aberrant activation of the erb-b2 receptor tyrosine kinase 2 (ERBB2) has been found to play a critical role in metastatic prostate cancer. In our previous study, we demonstrated that rs61552325 (Pro1140Ala) located in ERBB2 is strongly correlated to prostate cancer. Therefore, we initially studied the effect of rs61552325 on androgen-independent prostate cancer cell metastasis.

Results

Bioinformatic results demonstrated that the mutant Pro1140Ala likely decrease the stability of the ERBB2 protein and its interactions. The mean migration rate after 6 h for PC3 minor variant cells which carried the G allele was 1.28-fold higher than major variant PC3 cells that carried the C allele (P = 0.016). The mean invasion rate of DU145 putative minor variant cells was 0.40 reducer than negative control cells (P = 5.9E-04).

Methods

rs61552325 major variant (C allele) and minor variant (G allele) were produced by site directed mutagenesis and transfected into DU145 and PC3 cells. A wound healing assay was performed to compare migration abilities between alleles. After knocking down endogenous ERBB2 and then expressing the rs61552325 minor variant, invasion abilities were evaluated with a transwell assay using DU145 and PC3 cells.

Conclusions

Our data showed that the rs61552325 major variant decreases PC3 cell migration and its minor variant depresses DU145 cell invasion, suggesting that rs61552325 is likely an important change during prostate cancer invasion.

Multiple molecular modelling studies on some derivatives and analogues of glutamic acid as matrix metalloproteinase-2 inhibitors

Matrix metalloproteinase-2 (MMP-2) is a potential target in anticancer drug discovery due to its association with angiogenesis, metastasis and tumour progression. In this study, 67 glutamic acid derivatives, synthesized and evaluated as MMP-2 inhibitors, were taken into account for multi-QSAR modelling study (regression-based 2D-QSAR, classification-based LDA-QSAR, Bayesian classification QSAR, HQSAR, 3D-QSAR CoMFA and CoMSIA as well as Open3DQSAR). All these QSAR studies were statistically validated individually. Regarding the 3D-QSAR analysis, the Open3DQSAR results were better than CoMFA and CoMSIA, although all these 3D-QSAR models supported each other. The importance of biphenylsulphonyl moiety over phenylacetyl/naphthylacetyl moieties was established due to its association with favourable steric and hydrophobic characters. HQSAR, LDA-QSAR and Bayesian classification QSAR studies also suggested that the biphenylsulphonamido group was better than the phenylacetylcarboxamido function. Additionally, glutamines were proven to be far better inhibitors than isoglutamines. Observations obtained from the current study were revalidated and supported by the earlier reported molecular modelling studies. Depending on these observations, newer glutamic acid-based compounds may be designed further in future for potent MMP-2 inhibitory activity.

Multiple sites of vascular dilation or aneurysmal disease and matrix metalloproteinase genetic variants in patients with abdominal aortic aneurysm

OBJECTIVE

The objective of this study was to assess whether functional genetic polymorphisms of matrix metalloproteinases (MMPs) 1, 3, 9, and 12 are associated with arterial enlargements or aneurysms of the thoracic aorta or popliteal arteries in patients with abdominal aortic aneurysm (AAA).

METHODS

The associations between MMP1 (-1607 G in/del, rs1799750), MMP3 (-1171 A in/del rs35068180), MMP9 (13-26 CA repeats around -90, rs2234681, rs917576, rs917577), and MMP12 (G/T missense variation, rs652438) polymorphisms and enlargements or aneurysms of the thoracic aorta and popliteal arteries were tested in 169 consecutive AAA patients.

RESULTS

Thoracic aorta enlargement or aneurysm (TE/A; maximum diameter, >35 mm) was detected in 34 patients (20.1% prevalence). MMP9 rs2234681 microsatellite was the only genetic determinant of TE/A in AAA patients (P = .003), followed by hypercholesterolemia and antiplatelet use. Carriers of both alleles with ≥22 CA repeats had a 5.9 (95% confidence interval, 1.9-18.6; P < .0001) increased odds of TE/A, and a score considering all three variables showed 98% negative predictive value and 30% positive predictive value for thoracic aortic aneurysm detection. Eighty-two popliteal artery enlargements or aneurysms (diameter >10 mm) occurred in 55 patients (33.1% prevalence). Carriers of MMP12 rs652438 C allele showed an 18% (P = .006) increased diameter in popliteal arteries and a 2.8 (95% confidence interval, 1.3-6; P = .008) increased odds of popliteal artery enlargement or aneurysm compared with TT genotype.

CONCLUSIONS

Among patients with AAA, carriers of homozygous ≥22 CA repeats in MMP9 rs12234681 and of C allele in MMP12 rs652438 have a substantial risk of carrying thoracic and popliteal enlargements, respectively.

Synthesis of radioiodinated probes targeted toward matrix metalloproteinase-12

Matrix metalloproteinase-12 (MMP-12, macrophage elastase) is a member of the MMP family that is responsible for the degradation of extracellular matrix, and is associated with the inflammatory process of chronic obstructive pulmonary disease (COPD). COPD, characterized by progressive and irreversible airflow obstruction, is recently a major cause of mortality and morbidity worldwide. Herein, to develop radioiodinated probes for the early diagnosis of COPD, we designed and synthesized novel MMP-12-targeted dibenzofuran compounds (1-3) with a variety of linker structures (carbamate, amide, and sulfonamide). In competitive enzyme activity assays, it was revealed that the linker structures significantly affected the inhibitory activity against and selectivity for MMP-12. Compound 1, with carbamate linker, demonstrated potent MMP-12 inhibitory activity (IC₅₀ = 8.5 nM) compared to compound 2, with amide linker, and compound 3, with sulfonamide linker. Using bromo-substituted carbamate 13 as a radioiodination precursor, [¹²⁵I]1 was successfully prepared to high radiochemical purity (over 98%) and good specific radioactivity (4.1 GBq/μmol). These results suggest that radioiodinated compound 1 is potent as a novel MMP-12-targeted probe.

The Role of Matrix Metalloproteinases in Development, Repair, and Destruction of the Lungs

Normal gas exchange after birth requires functional lung alveolar units that are lined with epithelial cells, parts of which are intricately fused with microvascular capillaries. A significant phase of alveolar lung development occurs in the perinatal period, continues throughout early stages in life, and requires activation of matrix-remodeling enzymes. Failure to achieve an optimum number of alveoli during lung maturation can cause several untoward medical consequences including disabling obstructive and/or restrictive lung diseases that limit physiological endurance and increase mortality. Several members of the matrix metalloproteinase (MMP) family are critical in lung remodeling before and after birth; however, their resurgence in response to environmental factors, infection, and injury can also compromise lung function. Therefore, temporal expression, regulation, and function of MMPs play key roles in developing and maintaining adequate oxygenation under steady state, as well as in diseased conditions. Broadly, with the exception of MMP2 and MMP14, most deletional mutations of MMPs fail to perturb lung development; however, their individual absence can alter the pathophysiology of respiratory diseases. Specifically, under stressed conditions such as acute respiratory infection and allergic inflammation, MMP2 and MMP9 can play a protective role through bacterial clearance and production of chemotactic gradient, while loss of MMP12 can protect mice from smoke-induced lung disease. Therefore, better understanding of the expression and function of MMPs under normal lung development and their resurgence in response respiratory diseases could provide new therapeutic options in the future.

Targets of Neutrophil Influx and Weaponry: Therapeutic Opportunities for Chronic Obstructive Airway Disease

Neutrophils are important effector cells of antimicrobial immunity in an acute inflammatory response, with a primary role in the clearance of extracellular pathogens. However, in respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD), there is excessive infiltration and activation of neutrophils, subsequent production of reactive oxygen species, and release of serine proteases, matrix metalloproteinases, and myeloperoxidase—resulting in collateral damage as the cells infiltrate into the tissue. Increased neutrophil survival through dysregulated apoptosis facilitates continued release of neutrophil-derived mediators to perpetuate airway inflammation and tissue injury. Several target mechanisms have been investigated to address pathologic neutrophil biology and thereby provide a novel therapy for respiratory disease. These include neutrophil influx through inhibition of chemokine receptors CXCR2, CXCR1, and PI3Kγ signaling and neutrophil weaponry by protease inhibitors, targeting matrix metalloproteinases and neutrophil serine proteases. In addition, neutrophil function can be modulated using selective PI3Kδ inhibitors. This review highlights the latest advances in targeting neutrophils and their function, discusses the opportunities and risks of neutrophil inhibition, and explores how we might better develop future strategies to regulate neutrophil influx and function for respiratory diseases in dire need of novel effective therapies.

Matrix Metalloproteinase-28 Is a Key Contributor to Emphysema Pathogenesis

Chronic obstructive pulmonary disease (COPD) comprises chronic bronchitis and emphysema, and is a leading cause of morbidity and mortality. Because tissue destruction is the prominent characteristic of emphysema, extracellular proteinases, particularly those with elastolytic ability, are often considered to be key drivers in this disease. Several human and mouse studies have implicated roles for matrix metalloproteinases (MMPs), particularly macrophage-derived proteinases, in COPD pathogenesis. MMP-28 is expressed by the pulmonary epithelium and macrophage, and we have found that it regulates macrophage recruitment and polarization. We hypothesized that MMP-28 has contributory roles in emphysema via alteration of macrophage numbers and activation. Because of the established association of emphysema pathogenesis to macrophage influx, we evaluated the inflammatory changes and lung histology of Mmp28^-/- mice exposed to 3 and 6 months of cigarette smoke. At earlier time points, we found altered macrophage polarization in the smoke-exposed Mmp28^-/- lung consistent with other published findings that MMP-28 regulates macrophage activation. At both 3 and 6 months, Mmp28^-/- mice had blunted inflammatory responses more closely resembling nonsmoked mice, with a reduction in neutrophil recruitment and CXCL1 chemokine expression. By 6 months, Mmp28^-/- mice were protected from emphysema. These results highlight a previously unrecognized role for MMP-28 in promoting chronic lung inflammation and tissue remodeling induced by cigarette smoke and highlight another potential target to modulate COPD.

Evaluation of plasma leptin, tumor necrosis factor-α, and prealbumin as prognostic biomarkers during clinical recovery from acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Inflammatory and nutritional biomarkers have an important bearing on outcomes of acute exacerbations of chronic obstructive pulmonary disease (AECOPD), but the temporal profile of these compounds during an acute episode is unclear.

PATIENTS AND METHODS

Plasma leptin, prealbumin, and tumor necrosis factor-alpha (TNF-α) were estimated at baseline and before hospital discharge in patients with AECOPD.

RESULTS

A total of 82 patients were evaluated (66 males; mean (standard deviation) age, 61.6 (10.1) years. Of these, 74 subjects (90.2%) were current or former smokers, with median (range) pack-years of 15 (0-96), duration of COPD of 8 years (range, 2-25 years) and duration of current symptoms being 5 days (range, 1-30 days). Majority (41.5%) had type I (severe) exacerbation. During the current episode, 46 patients (58.9%) required mechanical ventilation for a median of 6 days (range, 1-34). The median duration of hospital stay was 13 days, (range, 1-110). At discharge, significant reduction was observed in dyspnea, total leukocyte count, erythrocyte sedimentation rate (ESR), partial pressure of carbon dioxide, hemoglobin, urea, creatinine, potassium, aspartate transferase, and TNF-α levels compared to baseline, whereas arterial pH, PO₂, serum albumin, prealbumin, and leptin significantly improved. No difference was seen in leptin, prealbumin, and TNF-α between patients with mild/moderate and severe exacerbation, or between patients who required or did not require mechanical ventilation. Change in leptin correlated with body mass index and change in ESR; no associations were observed between leptin, prealbumin, and TNF-α with other clinico-laboratory variables.

CONCLUSION

Plasma levels of novel inflammatory and nutritional biomarkers, i.e., leptin, TNF-α, and prealbumin are altered in AECOPD episodes and lag behind other parameters during recovery. These biomarkers are not reliable predictors of clinical outcomes in these patients.

Variability in proteinase-antiproteinase balance, nutritional status, and quality of life in stable chronic obstructive pulmonary disease due to tobacco and nontobacco etiology

Context:

Although the role of proteinase/antiproteinase imbalance in chronic obstructive pulmonary disease (COPD) due to tobacco is well established, information in COPD due to nontobacco etiology is sparse.

Aims:

To assess the variability in metalloproteinase activity in COPD related to tobacco and nontobacco causes.

Settings and Design:

This is a hospital-based, prospective, observational study.

Subjects and Methods:

Serum matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinases-1 (TIMP-1) were estimated in 200 subjects divided equally into four groups, i.e. COPD in tobacco smokers, COPD in nonsmokers but with exposure to biomass-related indoor air pollution, smokers without COPD, and nonsmoking healthy controls. Anthropometric skinfold measurements, quality of life (QOL) using St. George Respiratory Questionnaire, and exercise capacity using the 6-min walk test (6-MWT) were carried out. Groups were compared using analysis of variance and Kruskal–Wallis plus Mann–Whitney U-test to assess differences between groups. The Chi-square and Fisher's exact tests were used to evaluate associations among categorical variables. Spearman's rank correlation was calculated to assess the correlation between data.

Results:

Patients with COPD due to either tobacco or nontobacco etiology were older, more malnourished, had worse QOL, and poorer exercise capacity compared to non-COPD subjects. Triceps, subscapular, and suprailiac skinfold thicknesses were less in smokers with COPD than biomass-related COPD. MMP-9 and TIMP-1 levels were similar across all groups. TIMP-1 significantly correlated with 6-MWT among all groups.

Conclusions:

The protease-antiprotease balance in COPD is similar irrespective of the presence or absence of tobacco exposure but is related to poor exercise capacity.

Targeting oxidant-dependent mechanisms for the treatment of COPD and its comorbidities

Chronic obstructive pulmonary disease (COPD) is an incurable global health burden and is characterised by progressive airflow limitation and loss of lung function. In addition to the pulmonary impact of the disease, COPD patients often develop comorbid diseases such as cardiovascular disease, skeletal muscle wasting, lung cancer and osteoporosis. One key feature of COPD, yet often underappreciated, is the contribution of oxidative stress in the onset and development of the disease. Patients experience an increased burden of oxidative stress due to the combined effects of excess reactive oxygen species (ROS) and nitrogen species (RNS) generation, antioxidant depletion and reduced antioxidant enzyme activity. Currently, there is a lack of effective treatments for COPD, and an even greater lack of research regarding interventions that treat both COPD and its comorbidities. Due to the involvement of oxidative stress in the pathogenesis of COPD and many of its comorbidities, a unique therapeutic opportunity arises where the treatment of a multitude of diseases may be possible with only one therapeutic target. In this review, oxidative stress and the roles of ROS/RNS in the context of COPD and comorbid cardiovascular disease, skeletal muscle wasting, lung cancer, and osteoporosis are discussed and the potential for therapeutic benefit of anti-oxidative treatment in these conditions is outlined. Because of the unique interplay between oxidative stress and these diseases, oxidative stress represents a novel target for the treatment of COPD and its comorbidities.

Overexpression of matrix metalloproteinases in lung tissue of patients with primary spontaneous pneumothorax

BACKGROUND

Although blebs and bullae are frequently found in the apexes of lungs of patients with primary spontaneous pneumothorax (PSP), its pathogens remain unclear.

OBJECTIVES

To examine the role of proteases [matrix metalloproteinase (MMP)-2, MMP-7 and MMP-9] and antiproteases [tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2, TIMP-3 and TIMP-4] in the pathogenesis of PSP.

METHOD

Fifty consecutive PSP patients who received standard surgical care were enrolled in the study. Lung tissues from 20 patients with stage I non-small cell lung cancer were used as a control. Immunohistochemistry (IHC), reverse transcription-polymerase chain reaction (RT-PCR) and gelatin zymography were used to evaluate the expression of MMP and TIMP in the lung tissue of patients with PSP.

RESULTS

Overexpression of MMP-2, MMP-7 and MMP-9 was found in the afflicted lung by IHC, zymography and RT-PCR. By IHC, higher expression of MMP-2 and MMP-9 in PSP patients was identified in alveolar macrophages and type II pneumocytes (88 and 92% of patients in macrophages, and 72 and 70% of patients in type II pneumocytes, respectively). MMP-2, MMP-7 and MMP-9 expression in patients was higher in mesothelial cells (66, 76 and 76%). Overexpression of TIMP-2 was detected in the extracellular matrix around bullae and blebs. Expression levels of TIMP-1, TIMP-3 and TIMP-4 were negligible (<10% of cells) in both PSP patients and controls.

CONCLUSIONS

MMP-2, MMP-9, MMP-7 and TIMP-2 were upregulated in PSP lesions. These results suggest that an imbalance between the expression of proteases and antiproteases may be involved in the pathogeneses of PSP.

Clinical-radiological, histological and genetic analyses in a lung transplant recipient with Mounier-Kuhn syndrome and end-stage chronic obstructive pulmonary disease

BACKGROUND AND AIMS

The Mounier-Kuhn syndrome (MKS) is a rare disease characterized by a pathological dilation of the trachea and the bronchial system. The etiology of the disorder remains elusive, but genetic alterations and degradation of elastic fibers are thought to be involved in the pathogenesis. No causative treatment is available although transplantation is an option for end-stage disease. Here, we describe a patient suffering from MKS who received a double lung transplant at our department.

METHODS

Since a familial clustering of MKS is discussed in the literature, we performed a chromosomal analysis and an array-comparative genomic hybridization (CGH) to search for genetic abnormalities. At the time of transplantation, we collected samples from the bronchi and performed hematoxylin and eosin (HE), Elastic von-Gieson (EVG) and immunohistochemical stains of the explanted MKS bronchus, a control bronchus and of the inflammatory infiltrates. Specimens of main bronchi from the donor lung harvested for transplant served as control. Bronchial smears were taken from both main bronchi of the recipient for microbiological cultures.

RESULTS

No genetic alterations could be found in chromosomal analysis and in array-CGH. Histological analysis revealed a strong reduction of elastic fibers in the submucosal connective tissue and a diffuse inflammatory infiltrate, mainly comprised of CD4+ cells. In addition, immunohistochemistry showed increased matrix metalloproteinases (MMPs) protein expression of MMP-1, 2, 3 and 9.

CONCLUSIONS

Based on our findings, we hypothesize that MKS is a chronic inflammatory disease characterized by an MMP-mediated degradation of submucosal elastic fibers.

Matrix metalloproteinases and their pathological upregulation in multiple sclerosis: an overview

Matrix metalloproteinases (MMPs) are a family of extracellular proteases associated with extracellular matrix remodeling. They are involved in many physiological and reparative processes. MMPs can break down all extracellular constituents; therefore, their expression is very tightly regulated and their abnormal activity or over production has been linked to many diseases including multiple sclerosis (MS) which is a leading cause of non-traumatic disability in young adults in North America. Recently many studies, both in animals and humans, have been conducted to better elucidate the underlying causes, mechanisms and pathophysiology of MS. In this review, we discuss the potential role of pathological upregulation of MMPs in MS and future challenges which if properly addressed might help in development of potential cure for this disease.

Identification of molecular phenotypic descriptors of breast capsular contracture formation using informatics analysis of the whole genome transcriptome

Breast capsular contracture formation following silicone implant augmentation/reconstruction is a common complication that remains poorly understood. The aim of this study was to identify potential biomarkers implicated in breast capsular contracture formation by using, for the first time, whole genome arrays. Biopsy samples were taken from 18 patients (23 breast capsules) with Baker Grade I-II (Control) and Baker Grade III-IV (Contracted). Whole genome microarrays were performed and six significantly dysregulated genes were selected for further validation with quantitative reverse transcriptase polymerase chain reaction and immunohistochemistry. Hematoxylin and eosin was also carried out to compare the histological characteristics of control and contracted samples. Microarray results showed that aggrecan, tissue inhibitor of metalloproteinase 4 (TIMP4), and tumor necrosis factor superfamily (ligand) member 11 were significantly down-regulated in contracted capsules; while matrix metallopeptidase 12, serum amyloid A 1, and interleukin 8 (IL8) were significantly up-regulated. The dysregulation of aggrecan, tumor necrosis factor superfamily (ligand) member 11, TIMP4, and IL8 was validated by quantitative reverse transcriptase polymerase chain reaction (p < 0.05). Immunohistochemistry confirmed an increased protein expression for IL8 and matrix metallopeptidase 12 in contracted capsules (p < 0.05), and decreased protein expression of TIMP4 (p < 0.05). This study has shown, for the first time, a number of unique biomarkers of significance in capsular contracture formation. IL8 and TIMP4 may serve as potential key diagnostic, therapeutic, and prognostic biomarkers in capsular contracture formation.

Lilium lancifolium Thunb. extract attenuates pulmonary inflammation and air space enlargement in a cigarette smoke-exposed mouse model

ETHNOPHARMACOLOGICAL RELEVANCE

Lilium lancifolium Thunb. (Liliaceae) has long been used as a traditional medicine in Korea and China to treat bronchitis, pneumonia, and other pulmonary ailments.

AIM OF THE STUDY

Cigarette smoke (CS) is a major risk factor for the development of pulmonary inflammatory response; it also triggers pulmonary alveoli enlargement. In the present study, we investigate the effects of Lilium lancifolium Thunb. root extract on pulmonary inflammatory responses in a CS-exposed mouse model.

MATERIALS AND METHODS

Water extract of Lilium lancifolium Thunb. root was fed to C57BL/6 mice prior CS exposure every day for 3 weeks. The numbers of macrophages and neutrophils in bronchoalveolar lavage fluid (BALF) were counted. The relative inflammatory factors, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), monocyte chemotactic protein-1 (MCP-1), and matrix metalloproteinase-12 (MMP-12) were measured by real-time PCR, ELISA, or Western blot analysis. The average alveoli size was determined by lung histology.

RESULTS

Lilium lancifolium Thunb. root extract was found to significantly inhibit the numbers of macrophages and neutrophils in BALF due to CS exposure. Lilium lancifolium Thunb. root extract also reduced the protein secretion levels of TNF-α, IL-6, IL-1β, and MCP-1 in BALF and the RNA expression levels of TNF-α, IL-6, IL-1β, MCP-1, and MMP-12 in lung tissue compared with mice only exposed to CS. Moreover, MMP-12 in serum was down regulated in Lilium lancifolium Thunb. root extract treated mice compared with CS-exposed mice. Finally, a morphometric analysis of the lungs of Lilium lancifolium Thunb. root extract treated mice demonstrated a significant reduction in airspace size compared to mice only exposed to CS.

CONCLUSION

Our results show that Lilium lancifolium Thunb. root extract reduces lung inflammation and airspace enlargement in a CS-exposed mouse model. These data indicate that Lilium lancifolium Thunb. root extract is a therapeutic candidate for pulmonary inflammation and emphysema caused by CS.