MMP-8, MMP-9 and Neutrophil Elastase in Peripheral Blood and Exhaled Breath Condensate in COPD

Therapeutic potential of Cordyceps sinensis targeting oxidative stress and inflammatory response in the treatment of COPD rats: insights from metabolomics analysis

This study aimed to investigate the effects of wild Cordyceps sinensis on chronic obstructive pulmonary disease (COPD) rats through metabolomics approach, combined with biochemical parameters evaluations. Consequently, C. sinensis exhibited regulatory effects on the lung's metabolic profiles in COPD rats. Treatment with C. sinensis potentially modulated glycerophospholipid metabolism, glutathione metabolism, and tryptophan metabolism, thereby alleviating oxidative stress (by decreasing MDA and GSSG, while increasing SOD and GSH) and inflammatory response (by inhibiting TNF-α, IL-8, and MMP-9) in COPD rats while improving lung tissue damage.

Biomarkers in exhaled breath condensate as fingerprints of asthma, chronic obstructive pulmonary disease and asthma-chronic obstructive pulmonary disease overlap: a critical review

Asthma, chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap are the third leading cause of mortality around the world. They share some common features, which can lead to misdiagnosis. To properly manage these conditions, reliable markers for early and accurate diagnosis are needed. Over the past 20 years, many molecules have been investigated in the exhaled breath condensate to better understand inflammation pathways and mechanisms related to these disorders. Recently, more advanced techniques, such as sensitive metabolomic and proteomic profiling, have been used to obtain a more comprehensive understanding. This article reviews the use of targeted and untargeted metabolomic methodology to study asthma, COPD and asthma-COPD overlap.

The usefulness of MMP-9, TIMP-1 and MMP-9/TIMP-1 ratio for diagnosis and assessment of COPD severity

BACKGROUND

Inflammation, oxidative stress and an imbalance between proteases and protease inhibitors are recognized pathophysiological features of chronic obstructive pulmonary disease (COPD). The aim of this study was to evaluate serum levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in patients with COPD and to assess their relationship with lung function, symptom severity scores and recent acute exacerbations.

METHODS

In this observational cohort study, serum levels of MMP-9 and TIMP-1 and the MMP-9/TIMP-1 ratio in the peripheral blood of COPD patients with stable disease and healthy controls were determined, and their association with lung function (postbronchodilator spirometry, body plethysmography, single breath diffusion capacity for carbon monoxide), symptom severity scores (mMRC and CAT) and exacerbation history were assessed.

RESULTS

COPD patients (n = 98) had significantly higher levels of serum MMP-9 and TIMP-1 and a higher MMP-9/TIMP-1 ratio than healthy controls (n = 47) (p ≤ 0.001). The areas under the receiver operating characteristic curve for MMP-9, TIMP-1 and the MMP-9/TIMP-1 ratio for COPD diagnosis were 0.974, 0.961 and 0.910, respectively (all p < 0.05). MMP-9 and the MMP-9/TIMP-1 ratio were both negatively correlated with FVC, FEV_1, FEV₁/FVC, VC, and IC (all p < 0.05). For MMP-9, a positive correlation was found with RV/TLC% (p = 0.005), and a positive correlation was found for the MMP-9/TIMP-1 ratio with RV% and RV/TLC% (p = 0.013 and 0.002, respectively). Patients with COPD GOLD 3 and 4 presented greater MMP-9 levels and a greater MMP-9/TIMP-1 ratio compared to GOLD 1 and 2 patients (p ≤ 0.001). No correlation between diffusion capacity for carbon monoxide and number of acute exacerbations in the previous year was found.

CONCLUSIONS

COPD patients have elevated serum levels of MMP-9 and TIMP-1 and MMP-9/TIMP-1 ratio. COPD patients have an imbalance between MMP-9 and TIMP-1 in favor of a pro-proteolytic environment, which overall indicates the importance of the MMP-9/TIMP-1 ratio as a potential biomarker for COPD diagnosis and severity.

Matrix Metalloproteinases in Chronic Obstructive Pulmonary Disease

Matrix metalloproteinases (MMPs) are proteolytic enzymes that degrade proteins of the extracellular matrix and the basement membrane. Thus, these enzymes regulate airway remodeling, which is a major pathological feature of chronic obstructive pulmonary disease (COPD). Furthermore, proteolytic destruction in the lungs may lead to loss of elastin and the development of emphysema, which is associated with poor lung function in COPD patients. In this literature review, we describe and appraise evidence from the recent literature regarding the role of different MMPs in COPD, as well as how their activity is regulated by specific tissue inhibitors. Considering the importance of MMPs in COPD pathogenesis, we also discuss MMPs as potential targets for therapeutic intervention in COPD and present evidence from recent clinical trials in this regard.

Biological and Genetic Mechanisms of COPD, Its Diagnosis, Treatment, and Relationship with Lung Cancer

Chronic obstructive pulmonary disease (COPD) is one of the most prevalent chronic adult diseases, with significant worldwide morbidity and mortality. Although long-term tobacco smoking is a critical risk factor for this global health problem, its molecular mechanisms remain unclear. Several phenomena are thought to be involved in the evolution of emphysema, including airway inflammation, proteinase/anti-proteinase imbalance, oxidative stress, and genetic/epigenetic modifications. Furthermore, COPD is one main risk for lung cancer (LC), the deadliest form of human tumor; formation and chronic inflammation accompanying COPD can be a potential driver of malignancy maturation (0.8-1.7% of COPD cases develop cancer/per year). Recently, the development of more research based on COPD and lung cancer molecular analysis has provided new light for understanding their pathogenesis, improving the diagnosis and treatments, and elucidating many connections between these diseases. Our review emphasizes the biological factors involved in COPD and lung cancer, the advances in their molecular mechanisms' research, and the state of the art of diagnosis and treatments. This work combines many biological and genetic elements into a single whole and strongly links COPD with lung tumor features.

A2M Serves as Promising Biomarker for Chronic Obstructive Pulmonary Disease

Background

Chronic obstructive pulmonary disease (COPD) often associated with cigarette smoking. However, increasing evidence suggests that non-smoking COPD is much higher than previously thought. This study aims to identify a nonsmoking COPD biomarker and examined its value in diagnosis and prediction of acute exacerbation.

Methods

A total of 35 stable COPD patients, 70 acute exacerbation chronic obstructive pulmonary disease (AECOPD) patients and 35 healthy control subjects were included. Plasma α 2 macroglobulin (A2M) and matrix metalloproteinase-9 (MMP-9) levels were measured using the enzyme-linked immunosorbent assay (ELISA) method on all participants. Their association with clinical characteristics and lung function parameters were determined by regression analysis. Receiver operating characteristic (ROC) curve was used to determine the diagnostic sensitivity and specificity. Correlation coefficients were evaluated using Pearson's correlation.

Results

Plasma A2M concentration was decreased and MMP-9 concentration, MMP-9/A2M ratio were elevated in stable COPD patients compared with control groups. And MMP-9 expression was significantly higher in AECOPD patients. A2M level was increased in AECOPD patients with infection compared with those without. In addition, there was no statistical difference in A2M levels between smokers and nonsmokers COPD or healthy control subjects. Furthermore, A2M, MMP-9 and MMP-9/A2M were correlated with forced expiratory volume in one second (FEV₁)%, FEV₁/ forced vital capacity (FVC), CAT and mMRC score in COPD patients, but had no correlation with fraction of exhaled nitric oxide (FeNO) and concentration of alveolar nitric oxide (CaNO).

Conclusion

A2M is altered in peripheral blood of COPD patients and correlated with severity and infection. Moreover, there was no significant correlation between the change in A2M and smoking, FeNO and CaNO, suggesting A2M may reflect the overall rather than local inflammation in COPD patients and serve as a potential biomarker for nonsmoking COPD patients.

A novel role of Tinospora cordifolia in amelioration of cancer-induced systemic deterioration by taming neutrophil infiltration and hyperactivation

BACKGROUND

Cancer has emerged as a systemic disease which targets various organs thus challenging the overall physiology of the host. Recently, we have shown that hyperactive neutrophils infiltrate various organs of tumor bearing host and contribute to gradual systemic deterioration. Therefore, taming neutrophils via potent immunomodulators could be an appropriate therapeutic approach in regulating systemic damage. Tinospora cordifolia (TC), an Ayurvedic panacea, is known for its immense medicinal values in traditional literature and recent reports have also documented its immunomodulatory potential. However, whether TC can regulate neutrophils to exert its therapeutic effectiveness has not been deciphered so far.

METHODS

For the in vivo study, we utilized murine model of Dalton's Lymphoma (DL). T. cordifolia extract (TCE) treatment was scheduled at early, mid and advanced stages of tumor growth at a dose of 400 mg/kg b.w for 30 consecutive days. Effect of TCE on neutrophil infiltration was examined by immunostaining. Neutrophil elastase (NE) level in serum, ascitic fluid and various tissues was monitored by ELISA. Further, qPCR was performed to assess transcripts levels of NE, myeloperoxidase (MPO), metalloproteinases (MMP-8, MMP-9) and cathepsin G (CSTG) in various tissues. ROS level in tissue was assessed by DHE staining and organ function was assessed by histology post TCE treatment.

RESULTS

Our findings showed that TC treatment significantly reduced neutrophil count in peripheral blood and their infiltration in vital organs of tumor-bearing host. Further, it ameliorated neutrophil hyperactivation by down regulating the expression of its key cargoes including NE, MPO, MMP-8, MMP-9 and CSTG at early and mid stage of tumor growth. In addition, TC treatment prevented histopathological alterations and restored the normal serum enzyme levels at different stages of tumor growth. Importantly, TC treatment also showed significant reduction in tumor burden which was accompanied by a remarkable increase in survival of the tumor-bearing mice.

CONCLUSIONS

We conclude that T. cordifolia could limit systemic damage via regulating neutrophil infiltration and hyperactivation which can further lead to cancer control at both prophylactic and therapeutic level.

Exploration of the Pharmacological Mechanism of Bufei Nashen Pill in Treating Chronic Obstructive Pulmonary Disease Using Network Pharmacology Integrated Molecular Docking

Objective: Based on network pharmacological analysis and molecular docking verification, the therapeutic mechanism of Bufei Nashen Pill (BFNSP) in treating chronic obstructive pulmonary disease (COPD) is discussed. Methods: First, the active ingredients and therapeutic targets of BFNSP were determined based on literature and the Chinese medicine system pharmacology database. Relevant targets of COPD were determined using GeneCard, Therapeutic Target Database and Online Mendelian Inheritance in Man (OMIM). The con-targets of BFNSP and COPD were then obtained through the Veen platform, which were implemented in Cytoscape to build “Drug-Ingredients-Potential Target network.” Target gene function enrichment analysis and signal pathway analysis were performed based on STRING database, Database for Annotation, Visualization, and Integrated Discovery, and Kyoto Encyclopedia of Genes and Genomes Pathway database. Finally, SYBYL 2.2.1 software was used to finish docking. Results: In the Drug-Ingredients-Potential Targets network, 172 active ingredients and 183 potential targets were found. Enrichment analysis showed that potential targets mainly involve biological functions such as inflammation, reactive oxygen, and immunity. Molecular docking showed that the active ingredients of BFNSP had preferential interaction with interleukin 6, mitogen-activated protein kinase 1, SRC, epidermal growth factor receptor, and matrix metalloproteinase-9. Conclusion: BFNSP can be used to treat COPD by the regulation of inflammation, immunity, and hypoxia tolerance.

Fetal Lung Cells Transfer Improves Emphysematous Change in a Mouse Model of Neutrophil Elastase-Induced Lung Emphysema

Recently, several studies for lung regeneration have been reported. However, regenerating the lung tissue by the transfer of any cells directly to the lung has been hardly successful. The aim of this study was to evaluate the effect of fetal lung cells (FLCs) in a mouse model of lung emphysema. C57BL/6 mice were stimulated with neutrophil elastase (NE) intra-tracheally (i.t.) to generate lung emphysema. To collect fetal lung cells, C57BL/6-Tg (CAG-EGFP) mice were bred for 14 days. Before delivery, the bred mice were euthanized, and fetal lungs were harvested from the fetal mice and the cells were collected. The FLCs were transferred i.t. 24 h after the NE instillation. Four weeks after the NE instillation, mice were euthanized, and the samples were collected. The mean linear intercept (MLI) was significantly prolonged in the NE instillation group compared to the control group. However, in the FLCs transfer group stimulated with NE, the MLI became shorter than the NE-stimulated group without an FLCs transfer. This result shows that an FLCs transfer inhibited the progression of lung emphysema. Additionally, motility of the mice was also improved by the FLCs transfer. These results indicate that transfer of the FLCs, which were presumed to be progenitor cells for lung tissue, may improve the emphysematous change.

High-Density Lipoproteins: A Role in Inflammation in COPD

Chronic obstructive pulmonary disease (COPD) is a widespread disease associated with high rates of disability and mortality. COPD is characterized by chronic inflammation in the bronchi as well as systemic inflammation, which contributes significantly to the clinically heterogeneous course of the disease. Lipid metabolism disorders are common in COPD, being a part of its pathogenesis. High-density lipoproteins (HDLs) are not only involved in lipid metabolism, but are also part of the organism's immune and antioxidant defense. In addition, HDL is a versatile transport system for endogenous regulatory agents and is also involved in the removal of exogenous substances such as lipopolysaccharide. These functions, as well as information about lipoprotein metabolism disorders in COPD, allow a broader assessment of their role in the pathogenesis of heterogeneous and comorbid course of the disease.

Point-of-care COPD diagnostics: biomarkers, sampling, paper-based analytical devices, and perspectives

Chronic obstructive pulmonary disease (COPD) has become the third leading cause of global death. Insufficiency in early diagnosis and treatment of COPD, especially COPD exacerbations, leads to a tremendous economic burden and medical costs. A cost-effective and timely prevention requires decentralized point-of-care diagnostics at patients' residences at affordable prices. Advances in point-of-care (POC) diagnostics may offer new solutions to reduce medical expenditures by measuring salivary and blood biomarkers. Among them, paper-based analytical devices have been the most promising candidates due to their advantages of being affordable, biocompatible, disposable, scalable, and easy to modify. In this review, we present salivary and blood biomarkers related to COPD endotypes and exacerbations, summarize current technologies to collect human whole saliva and whole blood samples, evaluate state-of-the-art paper-based analytical devices that detect COPD biomarkers in saliva and blood, and discuss existing challenges with outlooks on future paper-based POC systems for COPD diagnosis and management.

Severe COVID-19 Shares a Common Neutrophil Activation Signature with Other Acute Inflammatory States

Severe COVID-19 patients present a clinical and laboratory overlap with other hyperinflammatory conditions such as hemophagocytic lymphohistiocytosis (HLH). However, the underlying mechanisms of these conditions remain to be explored. Here, we investigated the transcriptome of 1596 individuals, including patients with COVID-19 in comparison to healthy controls, other acute inflammatory states (HLH, multisystem inflammatory syndrome in children [MIS-C], Kawasaki disease [KD]), and different respiratory infections (seasonal coronavirus, influenza, bacterial pneumonia). We observed that COVID-19 and HLH share immunological pathways (cytokine/chemokine signaling and neutrophil-mediated immune responses), including gene signatures that stratify COVID-19 patients admitted to the intensive care unit (ICU) and COVID-19_nonICU patients. Of note, among the common differentially expressed genes (DEG), there is a cluster of neutrophil-associated genes that reflects a generalized hyperinflammatory state since it is also dysregulated in patients with KD and bacterial pneumonia. These genes are dysregulated at the protein level across several COVID-19 studies and form an interconnected network with differentially expressed plasma proteins that point to neutrophil hyperactivation in COVID-19 patients admitted to the intensive care unit. scRNAseq analysis indicated that these genes are specifically upregulated across different leukocyte populations, including lymphocyte subsets and immature neutrophils. Artificial intelligence modeling confirmed the strong association of these genes with COVID-19 severity. Thus, our work indicates putative therapeutic pathways for intervention.

A novel in vivo model for extracellular vesicle-induced emphysema

Chronic obstructive pulmonary disease (COPD) is a debilitating chronic disease and the third-leading cause of mortality worldwide. It is characterized by airway neutrophilia, promoting tissue injury through release of toxic mediators and proteases. Recently, it has been shown that neutrophil-derived extracellular vesicles (EVs) from lungs of patients with COPD can cause a neutrophil elastase–dependent (NE-dependent) COPD-like disease upon transfer to mouse airways. However, in vivo preclinical models elucidating the impact of EVs on disease are lacking, delaying opportunities for therapeutic testing. Here, we developed an in vivo preclinical mouse model of lung EV–induced COPD. EVs from in vivo LPS-activated mouse neutrophils induced COPD-like disease in naive recipients through an α-1 antitrypsin–resistant, NE-dependent mechanism. Together, these results show a key pathogenic and mechanistic role for neutrophil-derived EVs in a mouse model of COPD. Broadly, the in vivo model described herein could be leveraged to develop targeted therapies for severe lung disease.

A Novel Protective Role for Matrix Metalloproteinase-8 in the Pulmonary Vasculature

Rationale: Mechanical signaling through cell-matrix interactions plays a major role in progressive vascular remodeling in pulmonary arterial hypertension (PAH). MMP-8 (matrix metalloproteinase-8) is an interstitial collagenase involved in regulating inflammation and fibrosis of the lung and systemic vasculature, but its role in PAH pathogenesis remains unexplored. Objectives: To evaluate MMP-8 as a modulator of pathogenic mechanical signaling in PAH. Methods: MMP-8 levels were measured in plasma from patients with pulmonary hypertension (PH) and controls by ELISA. MMP-8 vascular expression was examined in lung tissue from patients with PAH and rodent models of PH. MMP-8-/- and MMP-8+/+ mice were exposed to normobaric hypoxia or normoxia for 4-8 weeks. PH severity was evaluated by right ventricular systolic pressure, echocardiography, pulmonary artery morphometry, and immunostaining. Proliferation, migration, matrix component expression, and mechanical signaling were assessed in MMP-8-/- and MMP-8+/+ pulmonary artery smooth muscle cells (PASMCs). Measurements and Main Results: MMP-8 expression was significantly increased in plasma and pulmonary arteries of patients with PH compared with controls and induced in the pulmonary vasculature in rodent PH models. Hypoxia-exposed MMP-8-/- mice had significant mortality, increased right ventricular systolic pressure, severe right ventricular dysfunction, and exaggerated vascular remodeling compared with MMP-8+/+ mice. MMP-8-/- PASMCs demonstrated exaggerated proliferation and migration mediated by altered matrix protein expression, elevated integrin-β3 levels, and induction of FAK (focal adhesion kinase) and downstream YAP (Yes-associated protein)/TAZ (transcriptional coactivator with PDZ-binding motif) activity. Conclusions: MMP-8 is a novel protective factor upregulated in the pulmonary vasculature during PAH pathogenesis. MMP-8 opposes pathologic mechanobiological feedback by altering matrix composition and disrupting integrin-β3/FAK and YAP/TAZ-dependent mechanical signaling in PASMCs.

PI3K signalling in chronic obstructive pulmonary disease and opportunities for therapy

Chronic obstructive pulmonary disease (COPD) is a chronic lung disease characterised by airway inflammation and progressive obstruction of the lung airflow. Current pharmacological treatments include bronchodilators, alone or in combination with steroids, or other anti-inflammatory agents, which have only partially contributed to the inhibition of disease progression and mortality. Therefore, further research unravelling the underlying mechanisms is necessary to develop new anti-COPD drugs with both lower toxicity and higher efficacy. Extrinsic signalling pathways play crucial roles in COPD development and exacerbations. In particular, phosphoinositide 3-kinase (PI3K) signalling has recently been shown to be a major driver of the COPD phenotype. Therefore, several small-molecule inhibitors have been identified to block the hyperactivation of this signalling pathway in COPD patients, many of them showing promising outcomes in both preclinical animal models of COPD and human clinical trials. In this review, we discuss the critically important roles played by hyperactivated PI3K signalling in the pathogenesis of COPD. We also critically review current therapeutics based on PI3K inhibition, and provide suggestions focusing on PI3K signalling for the further improvement of the COPD phenotype. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Increased Serum Levels of Matrix-metalloproteinase-9, Cyclo-oxygenase-2 and Prostaglandin E-2 in Patients with Chronic Obstructive Pulmonary Disease (COPD)

Chronic obstructive pulmonary disease (COPD), a heterogeneous lung disorder that is characterized by airflow obstruction and the third leading cause of death, globally. COPD is influenced by environmental and genetic factors. Here, we measured the serum level of matrix metalloproteinase-9 (MMP-9), cyclooxygenase-2 (COX-2) and prostaglandin E-2 (PGE-2) and reveal the correlation between their levels in COPD subjects. In this study, we included a total of 79 COPD and 79 healthy controls. We assessed demographic profile, risk factors, respiratory symptoms, clinical history, COPD Assessment Test (CAT) score and spirometry. Further, we determined the serum levels of MMP-9, COX-2 and PGE-2 by enzyme-linked immunosorbent assay (ELISA). The correlation between their serum levels was also determined. Among the studied population age, gender, body mass index and socioeconomic status were comparable. Serum levels of MMP-9, COX-2 and PGE-2 were significantly increased in the COPD group than in healthy controls (P < 0.0001). Moreover, MMP-9, COX-2 and PGE-2 levels were increased with the GOLD grades and CAT score (> 10). Serum levels of MMP-9, COX-2 and PGE-2 was enhanced in patients with larger clinical history (> 20 years) than those with lower clinical history (< 10 years). Serum levels of MMP-9 and COX-2; MMP-9 and PGE-2; COX-2 and PGE-2 showed a positive correlation (P < 0.0001) with the COPD group. Our data demonstrate that serum levels of MMP-9, COX-2 and PGE-2 were correlated with the GOLD grade, CAT score and clinical history of the COPD group, pointing that they can be used as a indicators to understand the disease progression.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-021-00973-2.

The aberrant cross-talk of epithelium-macrophages via METTL3-regulated extracellular vesicle miR-93 in smoking-induced emphysema

Cigarette smoke (CS), a complex chemical indoor air pollutant, induces degradation of elastin, resulting in emphysema. Aberrant cross-talk between macrophages and bronchial epithelial cells is essential for the degradation of elastin that contributes to emphysema, in which extracellular vesicles (EVs) play a critical role. The formation of N6-methyladenosine (m6A) is a modification in miRNA processing, but its role in the development of emphysema remains unclear. Here, we established that production of excess mature microRNA-93 (miR-93) in bronchial epithelial cells via enhanced m6A modification was mediated by overexpressed methyltransferase-like 3 (METTL3) induced by CS. Mature miR-93 was transferred from bronchial epithelial cells into macrophages by EVs. In macrophages, miR-93 activated the JNK pathway by targeting dual-specificity phosphatase 2 (DUSP2), which elevated the levels of matrix metalloproteinase 9 (MMP9) and matrix metalloproteinase 12 (MMP12) and induced elastin degradation, leading to emphysema. These results demonstrate that METTL3-mediated formation of EV miR-93, facilitated by m6A, is implicated in the aberrant cross-talk of epithelium-macrophages, indicating that this process is involved in the smoking-related emphysema. EV miR-93 may use as a novel risk biomarker for CS-induced emphysema.

Small Airways Disease, Biomarkers and COPD: Where are We?

The response to treatment and progression of Chronic Obstructive Pulmonary Disease (COPD) varies significantly. Small airways disease (SAD) is being increasingly recognized as a key pathological feature of COPD. Studies have brought forward pathological evidence of small airway damage preceding the development of emphysema and the detection of obstruction using traditional spirometry. In recent years, there has been a renewed interest in the early detection of SAD and this has brought along an increased demand for physiological tests able to identify and quantify SAD. Early detection of SAD allows early targeted therapy and this suggests the potential for altering the course of disease. The aim of this article is to review the evidence available on the physiological testing of small airways. The first half will focus on the role of lung function tests such as maximum mid-expiratory flow, impulse oscillometry and lung clearance index in detecting and quantifying SAD. The role of Computed Tomography (CT) as a radiological biomarker will be discussed as well as the potential of recent CT analysis software to differentiate normal aging of the lungs to pathology. The evidence behind SAD biomarkers sourced from blood as well as biomarkers sourced from sputum and broncho-alveolar lavage (BAL) will be reviewed. This paper focuses on CC-16, sRAGE, PAI-1, MMP-9 and MMP-12.

Potential use of biomarkers for the clinical evaluation of sarcoidosis

Sarcoidosis is a systemic granulomatous disease of unknown etiology and pathogenesis with a heterogeneous clinical presentation. In the appropriate clinical and radiological context and with the exclusion of other diagnoses, the disease is characterized by the pathological presence of non-caseating epithelioid cell granulomas. Sarcoidosis is postulated to be a multifactorial disease caused by chronic antigenic stimulation. The immunopathogenesis of sarcoidosis encompasses a complex interaction between the host, genetic factors and postulated environmental and infectious triggers, which result in granuloma development.The exact pathogenesis of the disease has yet to be elucidated, but some of the inflammatory pathways that play a key role in disease progression and outcomes are becoming apparent, and these may form the logical basis for selecting potential biomarkers.Biomarkers are biological molecules that are altered pathologically. To date, there exists no single reliable biomarker for the evaluation of sarcoidosis, either diagnostically or prognostically but new candidates are emerging. A diagnosis of sarcoidosis ideally requires a biopsy confirming non-caseating granulomas, but the likelihood of progression that requires intervention remains unpredictable. These challenging aspects could be potentially resolved by incorporating biomarkers into clinical practice for both diagnosis and monitoring disease activity.This review outlines the current knowledge on sarcoidosis with an emphasis on pulmonary sarcoidosis, and delineates the understanding surrounding the implication of biomarkers for the clinical evaluation of sarcoidosis.

The Potential Roles of Exosomes in Chronic Obstructive Pulmonary Disease

Currently, chronic obstructive pulmonary disease (COPD) is one of the most common chronic lung diseases. Chronic obstructive pulmonary disease is characterized by progressive loss of lung function due to chronic inflammatory responses in the lungs caused by repeated exposure to harmful environmental stimuli. Chronic obstructive pulmonary disease is a persistent disease, with an estimated 384 million people worldwide living with COPD. It is listed as the third leading cause of death. Exosomes contain various components, such as lipids, microRNAs (miRNAs), long non-coding RNAs(lncRNAs), and proteins. They are essential mediators of intercellular communication and can regulate the biological properties of target cells. With the deepening of exosome research, it is found that exosomes are strictly related to the occurrence and development of COPD. Therefore, this review aims to highlight the unique role of immune-cell-derived exosomes in disease through complex interactions and their potentials as potential biomarkers new types of COPD.

Ambient particulate matter attenuates Sirtuin1 and augments SREBP1-PIR axis to induce human pulmonary fibroblast inflammation: molecular mechanism of microenvironment associated with COPD

Evidences have shown a strong link between particulate matter (PM) and increased risk in human mortality and morbidity, including asthma, chronic obstructive pulmonary disease (COPD), respiratory infection, and lung cancer. However, the underlying toxicologic mechanisms remain largely unknown. Utilizing PM-treated human pulmonary fibroblasts (HPF) models, we analyzed gene expression microarray data and Ingenuity Pathway Analysis (IPA) to identify that the transcription factor sterol regulatory element-binding protein 1 (SREBP1) was the main downstream regulator of Sirtuin1 (SIRT1). Quantitative PCR and western blot results showed that SIRT1 inhibited SREBP1 and further downregulated Pirin (PIR) and Nod-like receptor protein 3 (NLRP3) inflammasome after PM exposure. Inhibitors of SIRT1, SREBP1, and PIR could reverse PM-induced inflammation. An in silico analysis revealed that PIR correlated with smoke exposure and early COPD. Immunohistochemical analysis of tissue microarrays from PM-fed mouse models was used to determine the association of PIR with PM. These data demonstrate that the SIRT1-SREBP1-PIR/ NLRP3 inflammasome axis may be associated with PM-induced adverse health issues. SIRT1 functions as a protector from PM exposure, whereas PIR acts as a predictor of PM-induced pulmonary disease. The SIRT1-SREBP1-PIR/ NLRP3 inflammasome axis may present several potential therapeutic targets for PM-related adverse health events.

Trans-4,4'-dihydroxystilbene ameliorates cigarette smoke-induced progression of chronic obstructive pulmonary disease via inhibiting oxidative stress and inflammatory response

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease resulted from airflow obstructions, and there is a driving requirement for novel and effective preventive and therapeutic agents of COPD. Nuclear factor-erythroid 2-related factor 2 (Nrf2) has been regarded to be a promising therapeutic target for COPD. Resveratrol is a natural Nrf2 activator with antioxidant and anti-inflammatory properties, however, its application is limited by its relative low efficiency and poor bioavailability. Herein, based on the skeleton of resveratrol, trans-4,4'-dihydroxystilbene (DHS) has been firstly identified to be an Nrf2 activator, which is more potent than the well-known sulforaphane (SF) and resveratrol. Our results indicate that DHS blocks Nrf2 ubiquitylation through specifically reacting with Cys151 cysteine in Keap1 protein to activate Nrf2-regulated defensive response, and thus enhances intracellular antioxidant capability. Furthermore, DHS relieves lipopolysaccharide (LPS)-stimulated inflammatory response via inhibition of NF-κB. Importantly, DHS significantly ameliorates pathological alterations (e.g. infiltration of leukocytes and fibrosis), downregulates the levels of oxidant biomarkers malondialdehyde (MDA) and 8-oxo-7,8-dihydro-2'-deoxyguanosin (8-oxo-dG), and inhibits the overproductions of inflammatory mediators [e.g. tumor necrosis factor α (TNF-α), cyclooxygenase-2 (COX-2), and matrix metalloproteinase-9 (MMP-9)] in a cigarette smoke (CS)-induced pulmonary impairment mice model. Taken together, this study demonstrates that DHS attenuates the CS-induced pulmonary impairments through inhibitions of oxidative stress and inflammatory response targeting Nrf2 and NF-κB in vitro and in vivo, and could be developed into a preventive agent against pulmonary impairments induced by CS.

Role of Pneumocystis jirovecii infection in chronic obstructive pulmonary disease progression in an immunosuppressed rat Pneumocystis pneumonia model

Pneumocystis jirovecii (P. jirovecii), an opportunistic fungal pathogen, is the primary cause of Pneumocystis pneumonia (PCP), which affects immunocompromised individuals and leads to high morbidity and mortality. P. jirovecii colonization is associated with development of chronic obstructive pulmonary disease (COPD) in patients with HIV infection, and also non-sufferers, and in primate models of HIV infection. However, the mechanisms underlying P. jirovecii infection in the pathogenesis of COPD have yet to be fully elucidated. To investigate the pathogenicity of P. jirovecii infection and its role in COPD development, the present study established a PCP rat model induced by dexamethasone sodium phosphate injection. Expression of COPD-related biomarkers, including matrix metalloproteinases (MMPs) MMP-2, MMP-8, MMP-9, and MMP-12, and heat shock protein-27 (HSP-27), were quantified in the rat PCP model using reverse transcription-quantitative polymerase chain reaction, ELISA, western blot analysis, immunohistochemistry and gelatin zymography. Body weight, COPD symptoms, and pulmonary histopathology were assessed. Inflammatory cell counts in splenic tissues were measured using flow cytometry. It was identified that MMP and HSP-27 expression increased in the PCP rats, which was in agreement with previous literature. Therefore, it was hypothesized that P. jirovecii infection may have an important role in COPD development.

How Do Innate Immune Cells Contribute to Airway Remodeling in COPD Progression?

Recently, the therapeutic potential of immune-modulation during the progression of chronic obstructive pulmonary disease (COPD) has been attracting increasing interest. However, chronic inflammatory response has been over-simplified in descriptions of the mechanism of COPD progression. As a form of first-line airway defense, epithelial cells exhibit phenotypic alteration, and participate in epithelial layer disorganization, mucus hypersecretion, and extracellular matrix deposition. Dendritic cells (DCs) exhibit attenuated antigen-presenting capacity in patients with advanced COPD. Immature DCs migrate into small airways, where they promote a pro-inflammatory microenvironment and bacterial colonization. In response to damage-associated molecular patterns (DAMPs) in lung tissue affected by COPD, neutrophils are excessively recruited and activated, where they promote a proteolytic microenvironment and fibrotic repair in small airways. Macrophages exhibit decreased phagocytosis in the large airways, while they demonstrate high pro-inflammatory potential in the small airways, and mediate alveolar destruction and chronic airway inflammation. Natural killer T (NKT) cells, eosinophils, and mast cells also play supplementary roles in COPD progression; however, their cellular activities are not yet entirely clear. Overall, during COPD progression, “exhausted” innate immune responses can be observed in the large airways. On the other hand, the innate immune response is enhanced in the small airways. Approaches that inhibit the inflammatory cascade, chemotaxis, or the activation of inflammatory cells could possibly delay the progression of airway remodeling in COPD, and may thus have potential clinical significance.

Severity of chronic obstructive pulmonary disease with 'exacerbator with emphysema phenotype' is associated with potential biomarkers

OBJECTIVE

The present study was designed to investigate the biomarkers levels of fractalkine (FKN), neutrophil elastase (NE) and matrix metalloproteinase-12 (MMP-12) in chronic obstructive pulmonary disease (COPD) with 'exacerbator with emphysema phenotype' and to evaluate the associations between the biomarkers levels and the severity of disease by spirometric measurements.

METHODS

A total of 84 COPD patients and 49 healthy controls were enrolled in our study. ELISA were utilised to detect the FKN, MMP-12 and NE in serum from all subjects.

RESULTS

FKN (p<0.001), NE (p=0.039) and MMP-12 (p<0.001) in serum of COPD patients showed higher levels than that of healthy control subjects. Serum FKN (p<0.001), MMP-12 (p<0.001) and NE (p=0.043) levels were significantly higher in severe and very severe COPD patients than that in mild and moderate COPD patients. Circulating FKN, MMP-12 and NE expression levels were significantly elevated (p<0.001) in COPD smokers compared with COPD non-smokers. The smoke pack years were negatively correlated with FEV₁%pred (r=-0.5036), FEV₁/FVC ratio (r=-0.2847) (FEV, forced expiratory volume; FVC, forced vital capacity). Similarly, we observed a strong positive correlation between the smoke pack years and serum levels of FKN (r=0.4971), MMP-12 (r=0.4315) and NE (r=0.2754). FEV₁%pred was strongly negatively correlated with cytokine levels of FKN (r=-0.4367), MMP-12 (r=-0.3295) and NE (r=-0.2684). Likewise, FEV₁/FVC ratio was negatively correlated with mediators of inflammation levels of FKN (r=-0.3867), MMP-12 (r=-0.2941) and NE (r=-0.2153).

CONCLUSION

Serum FKN, MMP-12 and NE concentrations in COPD patients are directly associated with the severity of COPD with 'exacerbator with emphysema phenotype'. This finding suggests that FKN, MMP-12 and NE might play an important role in the pathophysiology of COPD.

Expressions of MMP-12, TIMP-4, and Neutrophil Elastase in PBMCs and Exhaled Breath Condensate in Patients with COPD and Their Relationships with Disease Severity and Acute Exacerbations

OBJECTIVE

The purpose of this study was to compare matrix metalloproteinase-12 (MMP-12), neutrophil elastase (NE), and tissue inhibitor of metalloproteinase-4 (TIMP-4) in peripheral blood of patients with chronic obstructive pulmonary disease (COPD) and controls. At the same time, MMP-12, NE, and TIMP-4 in exhaled breath condensate (EBC) were also evaluated.

METHODS

Peripheral blood and EBC samples from COPD patients and healthy controls were collected. In serum and EBC, MMP-12, NE, and TIMP-4 proteins were detected by enzyme-linked immunoassays. The mRNA expression levels of MMP-12, NE, and TIMP-4 in peripheral blood mononuclear cells (PBMCs) were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

The concentration of TIMP-4 protein in EBC was lower in patients with COPD (P < 0.001). MMP-12 (P = 0.046), NE (P = 0.027), and TIMP-4 (P = 0.005) proteins in serum of patients with COPD showed higher levels of concentration. The mRNA of MMP-12 (P = 0.0067), NE (P = 0.0058), and TIMP-4 (P = 0.0006) in PBMCs of COPD patients showed higher expression levels. Compared with stable patients, mRNA expression level of NE (P = 0.033) in PBMCs of patients with acute exacerbation of COPD was increased. There were differences in the ratio of MMP-12/TIMP-4 in PBMC (P = 0.0055), serum (P = 0.0427), and EBC (P = 0.0035) samples between COPD patients and healthy controls. The mRNA expression of MMP-12 (r = -0.3958, P = 0.0186) and NE (r = -0.3694, P = 0.0290) in COPD patients was negatively correlated with pulmonary function. However, the mRNA expression of TIMP-4 (r = 0.2871, P = 0.0945) in PBMCs was not correlated with the FEV1 of the pulmonary function. Serum MMP-12 level was positively correlated with the MMP-12 level in EBC (P = 0.0387). The level of TIMP-4 in serum was not correlated with the level in the EBC sample (P = 0.4332).

CONCLUSION

The expression levels of MMP-12, NE, and TIMP-4 in PBMCs and serum were elevated in COPD patients. In PBMCs of COPD patients, the mRNA expression level of NE may predict acute exacerbation, and MMP-12 mRNA expression level may be used to reflect the severity of airflow limitation. However, to better assess their diagnostic or prognostic value, larger studies are necessary.

Inflammatory mediators in exhaled breath condensate and peripheral blood of healthy donors and stable COPD patients

Objective: The aim of this work was to compare matrix metalloproteinase-9 and -12, tissue inhibitor of metalloproteinase-1 and -4, and neutrophil elastase in exhaled breath condensate (EBC) and peripheral blood of patients with COPD. Methods: Peripheral blood and EBC samples from COPD patients and healthy donors were collected. In serum and EBC, MMP-9, MMP-12, NE, TIMP-1, and TIMP-4 proteins were detected by ELISA. The mRNA expression levels of MMP-9, MMP-12, NE, TIMP-1, and TIMP-4 in peripheral blood mononuclear cells (PBMCs) were analyzed by qRT-PCR. Results: The protein levels of MMP-9 (p=.034) and MMP-12 (p=.041) in the EBC of COPD smokers were higher than those of COPD never-smokers. The concentrations of TIMP-1 (p=.072) and TIMP-4 (p=.084) in the EBC of COPD smokers were higher than those of COPD never-smokers; however, the difference was not statistically significant. MMP-9 (r=-0.78, p<.0001) and TIMP-1 (r=-0.71, p<.0001) levels in EBC were significantly negatively correlated with pulmonary function FEV1%pred. The protein levels of MMP-12 (r=-0.37, p=.034) and TIMP-4 (r=-0.34, p=.041) were also negatively correlated with FEV1%pred. The expression of MMP-9, MMP-12, NE, TIMP-1, and TIMP-4 in PBMCs and serum of COPD smokers were significantly higher than those of control never-smokers (p<.05). Conclusions: Exhaled MMP-9, MMP-12, TIMP-1, and TIMP-4 levels increased in stable COPD patients and were negatively correlated with FEV1%pred, which suggests the usefulness of their measurement in EBC for the monitoring of airway inflammation. However, to better assess their diagnostic or prognostic value, larger studies are necessary.

Data-independent acquisition-based quantitative proteomic analysis reveals differences in host immune response of peripheral blood mononuclear cells to sepsis

This study was aimed to uncover proteins that are differentially expressed in sepsis. Data-independent acquisition (DIA) was used for analysis to identify differentially expressed proteins in peripheral blood mononuclear cells (PBMCs) of patients. A total of 24 non-septic intensive care unit (ICU) patients, 11 septic shock patients and 27 patients diagnosed with sepsis were recruited for the mass spectrometry (MS) discovery. PBMCs were isolated from routine blood samples and digested into peptides. A DIA workflow was developed using a quadrupole-Orbitrap liquid chromatography LC-MS system, and mass spectra peaks were extracted by Skyline software. Orthogonal partial least-squares discriminant analysis (OPLS-DA) and partial least-squares discriminant analysis (PLS-DA) were applied to distinguish the patient groups at the level of fragment ion and peptide. Differentially expressed proteins in the patient groups were verified by enzyme-linked immunosorbent assay (ELISA). Receiver-operating characteristic (ROC) curves were used to evaluate the protein expression. A total of 1062 fragment ions and 122 proteins were identified in the MS-DIA analysis conducted by Skyline software. Using gene ontology clustering analysis, we discovered that 51 of the 122 identified proteins were associated with biological processes, including carbon metabolism, biosynthesis of antibiotics, platelet activation, bacterial invasion of epithelial cells and complement, and coagulation cascades. Among them, five proteins (high-mobility group box1 [HMGB1], matrix metalloproteinase 8 [MMP8], neutrophil gelatinase-associated lipocalin [NGAL], lactotransferrin [LTF] and grancalcin [GCA]) were identified by ELISA as closely related to the development of sepsis. The ROC curves displayed good sensitivity and specificity.

Relationship Between Circulating Serpina3g, Matrix Metalloproteinase-9, and Tissue Inhibitor of Metalloproteinase-1 and -2 with Chronic Obstructive Pulmonary Disease Severity

Chronic obstructive pulmonary disease (COPD) is influenced by genetic and environmental factors. A protease-antiprotease imbalance has been suggested as a possible pathogenic mechanism for COPD. Here, we examined the relationship between circulating serpina3g, matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 and -2 (TIMP-1 and -2, respectively) and severity of COPD. We included 150 stable COPD patients and 35 control subjects in the study. The COPD patients were classified into four groups (I, II, III, and IV), according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines based on the severity of symptoms and the exacerbation risk. Plasma serpina3g, MMP-9, and TIMP-1 and -2 concentrations were significantly higher in the all patients than in control subjects. Plasma serpina3g, MMP-9, and TIMP-1 and -2 concentrations were significantly higher in groups III and IV than in groups I and II. A negative correlation between serpina3g, MMP-9, and TIMP-1 and -2 levels and the forced expiratory volume in 1 s (FEV1) was observed. MMP-9 concentration and the MMP-9/TIMP-1 ratio were higher in patients with emphysema than in other phenotypes (both with p < 0.01). The findings of this study suggest that circulating serpina3g, MMP-9, and TIMP-1 and -2 levels may play an important role in airway remodeling in COPD pathogenesis. Disrupted protease-antiprotease imbalance in patients with COPD is related to the presence of airway injury. MMP-9 concentration and the MMP-9/TIMP-1 ratio are the best predictors of emphysema in COPD patients.

Activated PMN Exosomes: Pathogenic Entities Causing Matrix Destruction and Disease in the Lung

Here, we describe a novel pathogenic entity, the activated PMN (polymorphonuclear leukocyte, i.e., neutrophil)-derived exosome. These CD63+/CD66b+ nanovesicles acquire surface-bound neutrophil elastase (NE) during PMN degranulation, NE being oriented in a configuration resistant to α1-antitrypsin (α1AT). These exosomes bind and degrade extracellular matrix (ECM) via the integrin Mac-1 and NE, respectively, causing the hallmarks of chronic obstructive pulmonary disease (COPD). Due to both ECM targeting and α1AT resistance, exosomal NE is far more potent than free NE. Importantly, such PMN-derived exosomes exist in clinical specimens from subjects with COPD but not healthy controls and are capable of transferring a COPD-like phenotype from humans to mice in an NE-driven manner. Similar findings were observed for another neutrophil-driven disease of ECM remodeling (bronchopulmonary dysplasia [BPD]). These findings reveal an unappreciated role for exosomes in the pathogenesis of disorders of ECM homeostasis such as COPD and BPD, providing a critical mechanism for proteolytic damage.

High Serum Fractalkine/CX3CL1 in Patients with Chronic Obstructive Pulmonary Disease: Relationship with Emphysema Severity and Frequent Exacerbation

OBJECTIVE

The purpose of this study was to investigate the relationship between serum fractalkine (CX3CL1/FKN) level and the multi-slice spiral computed tomography (MSCT) emphysema index in Chinese patients with chronic obstructive pulmonary disease (COPD).

METHODS

We detected chemokine CX3CL1 in serum from 95 Chinese patients with COPD by using an enzyme-linked immunosorbent assay. According to the MSCT emphysema index, the selected cases were divided into an emphysema-dominant group (n = 25) and a non-emphysema-dominant group (n = 70).

RESULTS

There were significant differences in body mass index and lung function between the two groups. The serum level of CX3CL1 in the emphysema-dominant group was significantly higher than that in the non-emphysema-dominant group. Through multivariate logistic regression analysis, it was found that high serum CX3CL1 levels were independently associated with emphysema, with a relative risk of 2.617 (95% CI 1.018-6.121; P = 0.029). The percentage of frequent acute exacerbations during the first year of follow-up was significantly higher in the high-level serum CX3CL1 group (P = 0.039). After 3 years of follow-up, there was no significant difference in the CT emphysema index between the high and low serum CX3CL1 groups (P = 0.503).

CONCLUSION

Our results suggest that the serum level of CX3CL1 is related to the MSCT emphysema index. Chemokine CX3CL1 might be a useful predictor for identifying frequent exacerbation and emphysema severity in patients with COPD.

Proteases and Their Inhibitors in Chronic Obstructive Pulmonary Disease

In the context of respiratory disease, chronic obstructive pulmonary disease (COPD) is the leading cause of mortality worldwide. Despite much development in the area of drug development, currently there are no effective medicines available for the treatment of this disease. An imbalance in the protease: Antiprotease ratio in the COPD lung remains an important aspect of COPD pathophysiology and several studies have shown the efficacy of antiprotease therapy in both in vitro and in vivo COPD models. However more in-depth studies will be required to validate the efficacy of lead drug molecules targeting these proteases. This review discusses the current status of protease-directed drugs used for treating COPD and explores the future prospects of utilizing the potential of antiprotease-based therapeutics as a treatment for this disease.

Analysis and validation of a new extended method for estimating plasma free cortisol including neutrophil elastase and competition from other steroids

A non-linear mechanistic model for the distribution of cortisol in plasma on free and bound forms is proposed. The influence of progesterone, testosterone and neutrophil elastase on the cortisol distribution in the blood is investigated. The activity of neutrophil elastase is directly included in the model with the concentration of elastase and the kinetic constants describing the activity of elastase collected in one single input variable. The model is very sensitive towards this input variable and fits data excellently, when it is allowed to be subject specific. The analysis shows that steroids such as testosterone with low affinity for corticosteroid-binding globulin (CBG) do not significantly influence the concentration of free cortisol. Progesterone has a high affinity for CBG, but low plasma concentrations compared to cortisol. Contrary to expectations, progesterone is shown to impact the distribution of cortisol in plasma both under circumstances with high levels as seen in pregnancy and during the normal menstrual cycle of women. Comparing the predictions of our model with predictions made with the equilibrium models by Coolens et al. [1], Dorin et al. [2] and Nguyen et al. [3] shows that the models differ considerably not only in their predictions for free cortisol, but also for cortisol on bound forms; i.e. bound to albumin, intact CBG and elastase-cleaved CBG. Disregarding some of the smallest terms of the model equations a reduced version of the model in form of a fourth order polynomial equation is obtained. The reduced version of the model performs almost identically to the full version and serves as a new formula for calculating the plasma free cortisol concentration.