New Insights into the Role of NLRP3 Inflammasome in Pathogenesis and Treatment of Chronic Obstructive Pulmonary Disease

Andrographolide Attenuates NLRP3 Inflammasome Activation and Airway Inflammation in Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose

The aim of this study is to uncover the anti-inflammatory propertity of andrographolide (AGP) in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and the underlying mechanisms related to the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome pathway.

Methods

An in vivo experiment was conducted on murine model of AECOPD through endotracheal atomization of elastase and lipopolysaccharide (LPS). Intraperitoneal AGP was administered four times. NLRP3 inflammasome pathway molecules were examined using real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. By using enzyme-linked immunosorbent assay (ELISA), we tested interleukin (IL)-1β levels in bronchoalveolar lavage fluid. An in vitro study was conducted to determine how AGP impacts the NLRP3 inflammasome in THP-1 derived macrophages. The levels of molecules involved in the pathway were measured. Furthermore, molecular docking analyses were carried out to investigate the interactions between AGP and pathway targets.

Results

In the in vivo study, NLRP3 inflammasome activation was observed in mice experiencing AECOPD. The administration of high-dose AGP demonstrated a mitigating effect on inflammatory cells infiltration in the lungs. Moreover, AGP administration effectively suppressed the expression of NLRP3, apoptosis associated speck-like protein that contains a CARD (PYCARD), cysteinyl aspartate-specific protease-1 (Caspase-1), IL-1β, and IL-18 at both the genetic and protein levels. In the in vitro experiment, IL-1β levels were significantly elevated in THP-1 derived macrophages with activated inflammasome compared to the control group. Furthermore, the downregulation of NLRP3, CASP1, and IL1B genes was observed upon the inhibition of NLRP3 expression through small interfering RNA (siRNA). AGP demonstrated inhibitory effects on the gene expression and protein levels of NLRP3, Caspase-1, and IL-1β. Additionally, molecular docking analysis confirmed that AGP exhibited a favorable binding affinity with all five targets of the pathway.

Conclusion

AGP effectively inhibited NLRP3 inflammasome activation and mitigated the inflammatory reaction of AECOPD both in animal models and in vitro experiments, highlighting the potential of AGP as a treatment for AECOPD with anti-inflammatory properties.

Effects of Combustible Cigarettes and Electronic Nicotine Delivery Systems on the Development and Progression of Chronic Lung Inflammation in Mice

INTRODUCTION

Although detrimental effects of combustible cigarettes (CCs) on the progression of lung inflammatory diseases are well known, changes in electronic nicotine delivery systems (ENDS)-exposed lung-infiltrated immune cells are still unrevealed.

AIMS AND METHODS

The analysis of blood gas parameters, descriptive and quantitative histology of lung tissues, determination of serum cytokines, intracellular staining, and flow cytometry analysis of lung-infiltrated immune cells were used to determine the differences in the extent of lung injury and inflammation between mice from experimental (CC and ENDS-exposed animals) and control groups (Air-exposed mice).

RESULTS

Continuous exposition to either CCs or ENDS induced severe systemic inflammatory response, increased activation of NLRP3 inflammasome in neutrophils and macrophages and enhanced dendritic cell-dependent activation of Th1 and Th17 cells in the lungs. ENDS induced less severe immune response than CCs. Serum concentrations of inflammatory cytokines were significantly lower in the samples of ENDS-exposed mice. Compared to CCs, ENDS recruited lower number of circulating leukocytes in injured lungs and had less capacity to induce CD14/TLR2-dependent activation of NLRP3 inflammasome in lung-infiltrated neutrophils and macrophages. ENDS-primed dendritic cells had reduced capacity for the generation of Th1 and Th17 cell-driven lung inflammation. Accordingly, extensive immune cell-driven lung injury resulted in severe respiratory dysfunction in CCs-exposed mice, while ENDS caused moderate respiratory dysfunction in experimental animals.

CONCLUSIONS

Continuous exposition to either CCs or ENDS induced immune cell-driven lung damage in mice. ENDS triggered immune response, which was less potent than inflammatory response elicited by CCs and, therefore, caused less severe lung injury and inflammation.

IMPLICATIONS

This is the first study that compared the effects of CCs and ENDS on lung-infiltrated immune cells. Although both CCs and ENDS elicited systemic inflammatory response, immune cell-driven lung injury and inflammation were less severe in ENDS-exposed than in CC-exposed animals. Continuous exposition to ENDS-sourced aerosols was less harmful for respiratory function of experimental animals than CC-derived smoke.

The pomegranate-derived peptide Pug-4 alleviates nontypeable Haemophilus influenzae-induced inflammation by suppressing NF-kB signaling and NLRP3 inflammasome activation

The respiratory pathogen nontypeable Haemophilus influenzae (NTHi) is the most common cause of exacerbation of chronic obstructive pulmonary disease (COPD), of which an excessive inflammatory response is a hallmark. With the limited success of current medicines there is an urgent need for the development of novel therapeutics that are both safe and effective. In this study, we explored the regulatory potential of pomegranate-derived peptides Pug-1, Pug-2, Pug-3, and Pug-4 on NTHi-induced inflammation. Our results clearly showed that to varying degrees the Pug peptides inhibited NTHi-induced production of IL-1β, a pivotal cytokine in COPD, and showed that these effects were not related to cytotoxicity. Pug-4 peptide exhibited the most potent inhibitory activity. This was demonstrated in all studied cell types including murine (RAW264.7) and human (differentiated THP-1) macrophages as well as human lung epithelial cells (A549). Substantial reduction by Pug-4 of TNF-α, NO and PGE2 in NTHi-infected A549 cells was also observed. In addition, Pug-4 strongly inhibited the expression of nuclear-NF-κB p65 protein and the NF-κB target genes (determined by IL-1β, TNF-α, iNOS and COX-2 mRNA expression) in NTHi-infected A549 cells. Pug-4 suppressed the expression of NLRP3 and pro-IL-1β proteins and inhibited NTHi-mediated cleavage of caspase-1 and mature IL-1β. These results demonstrated that Pug-4 inhibited NTHi-induced inflammation through the NF-κB signaling and NLRP3 inflammasome activation. Our findings herein highlight the significant anti-inflammatory activity of Pug-4, a newly identified peptide from pomegranate, against NTHi-induced inflammation. We therefore strongly suggest the potential of the Pug-4 peptide as an anti-inflammatory medicine candidate for treatment of NTHi-mediated inflammation.

CD146 deficiency aggravates chronic obstructive pulmonary disease via the increased production of S100A9 and MMP-9 in macrophages

Chronic obstructive pulmonary disease (COPD) is a leading cause of global death. As a molecule beyond adhesion, CD146 is involved in COPD pathogenesis. However, the mechanisms of CD146 in COPD remain largely elusive. We hypothesized that CD146 regulates the production of matrix metalloproteinase-9 (MMP-9) in macrophages and thereby contributes to COPD. Here, we constructed a murine model of COPD using lipopolysaccharide (LPS) and porcine pancreatic elastase (PPE). In COPD-like mice, LPS and PPE decreased the pulmonary expression of CD146. MMP-9 expression and bioactivity were increased in CD146 knockout COPD-like mice. In vitro, LPS decreased CD146 expression in macrophages. With or without LPS challenge, CD146-defective macrophages produced more MMP-9. Transcriptome analysis based on next-generation sequencing (NGS) revealed that S100A9 regulated MMP-9 production in CD146-defective macrophages. Targeting S100A9 with paquinimod decreased lung inflammation and alleviated alveolar destruction in COPD-like mice. Collectively, our study suggests that CD146 negatively regulates MMP-9 production in macrophages via the S100A9 pathway in COPD.

Identification of Potential Differentially-Methylated/Expressed Genes in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease that causes obstructed airflow from the lungs. DNA methylation can regulate gene expression. Understanding the potential molecular mechanism of COPD is of great importance. The aim of this study was to find differentially methylated/expressed genes in COPD. DNA methylation and gene expression profiles in COPD were downloaded from the dataset, followed by functional analysis of differentially-methylated/expressed genes. The potential diagnostic value of these differentially-methylated/expressed genes was determined by receiver operating characteristic (ROC) analysis. Expression validation of differentially-methylated/expressed genes was performed by in vitro experiment and extra online datasets. Totally, 81 hypermethylated-low expression genes and 121 hypomethylated-high expression genes were found in COPD. Among which, 9 core hypermethylated-low expression genes (CD247, CCR7, CD5, IKZF1, SLAMF1, IL2RB, CD3E, CD7 and IL7R) and 8 core hypomethylated-high expression genes (TREM1, AQP9, CD300LF, CLEC12A, NOD2, IRAK3, NLRP3 and LYZ) were identified in the protein-protein interaction (PPI) network. Moreover, these genes had a potential diagnostic utility for COPD. Some signaling pathways were identified in COPD, including T cell receptor signaling pathway, cytokine-cytokine receptor interaction, hematopoietic cell lineage, HTLV-I infection, endocytosis and Jak-STAT signaling pathway. In conclusion, differentially-methylated/expressed genes and involved signaling pathways are likely to be associated with the process of COPD.

Mitochondrial damage-associated molecular patterns in chronic obstructive pulmonary disease: Pathogenetic mechanism and therapeutic target

Chronic obstructive pulmonary disease (COPD) is a common inflammatory airway disease characterized by enhanced inflammation. Recent studies suggest that mitochondrial damage-associated molecular patterns (DAMPs) may play an important role in the regulation of inflammation and are involved in a serial of inflammatory diseases, and they may also be involved in COPD. This review highlights the potential role of mitochondrial DAMPs during COPD pathogenesis and discusses the therapeutic potential of targeting mitochondrial DAMPs and their related signaling pathways and receptors for COPD. Research progress on mitochondrial DAMPs may enhance our understanding of COPD inflammation and provide novel therapeutic targets.

Impact of NLRP3 gene polymorphisms (rs10754558 and rs10733113) on HPV infection and cervical cancer in southern Chinese population

OBJECTIVE

Mutations in the NLRP3gene have previously been linked to certain forms of cancer, but there have not been any specific studies examining the association between NLRP3 polymorphisms and cervical cancer (CC). This study was therefore designed to investigate the effect of NLRP3 gene polymorphisms on HPV infection and cervical cancer in southern Chinese population.

METHODS

Multiplex PCR and next-generation sequencing approaches were used to assess the NLRP3 rs10754558 and rs10733113 polymorphisms in 404 cervical lesion patients, including 227 diagnosed with CC and 177 diagnosed with cervical intraepithelial neoplasia(CIN), with 419 healthy female controls being included for comparison. Correlations between the rs10754558 and rs10733113 genotypes and alleles in these patients and CC and CIN were then analyzed.

RESULTS

No correlations were found between NLRP3 rs10754558 and rs10733113 and human papillomavirus(HPV) infection status. Relative to the healthy control group, the NLRP3 rs10754558 GG genotype, CG + GG genotype, and G allele frequencies were significantly increased among patients with cervical lesions (CC and CIN) (OR = 1.815,P = 0.013;OR = 1.383, P = 0.026; OR = 1.284, P = 0.014,respectively), whereas no such differences were observed for rs10733113. A higher cervical lesion risk was detected for patients over the age of 45 exhibiting the rs10754558 GG genotype (OR = 1.848, P = 0.040). Additionally, the risk of CC was elevated in patients with the rs10754558 GG genotype or the G allele relative to patients with the CC genotype or the C allele(OR = 1.830, P = 0.029; OR = 1.281, P = 0.039). The rs10733113 genotypes or alleles were not significantly associated with CC risk (P > 0.05). No association between rs10754558 and rs10733113 genotypes and CC patient clinicopathological features were observed (P > 0.05). Serum NLRP3, IL-1β, and IL-18 levels were significantly elevated in CC patients relative to healthy controls(P < 0.05). Relative to the CC genotype, CC patients harboring the rs10754558 GG genotype exhibited significantly elevated IL-1β and IL-18 levels(P < 0.05).

CONCLUSION

The rs10754558 polymorphism in the NLRP3 gene may contribute to an elevated risk of CC, although it is not significantly correlated with HPV infection and CC progression.

Mechanism of KLF9 in airway inflammation in chronic obstructive pulmonary

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is an airway-associated lung disorder, resulting in airway inflammation. This article aimed to explore the role of the krüppel-like factor 9 (KLF9)/microRNA (miR)-494-3p/phosphatase and tensin homolog (PTEN) axis in airway inflammation and pave a theoretical foundation for the treatment of COPD.

METHODS

The COPD mouse model was established by exposure to cigarette smoke, followed by measurements of total cells, neutrophils, macrophages, and hematoxylin and eosin staining. The COPD cell model was established on human lung epithelial cells BEAS-2B using cigarette smoke extract. Cell viability was assessed by cell counting kit-8 assay. miR-494-3p, KLF9, PTEN, and NLR family, pyrin domain containing 3 (NLRP3) levels in tissues and cells were measured by quantitative real-time polymerase chain reaction or Western blot assay. Inflammatory factors (TNF-α/IL-6/IL-8/IFN-γ) were measured by enzyme-linked immunosorbent assay. Interactions among KLF9, miR-494-3p, and PTEN 3'UTR were verified by chromatin immunoprecipitation and dual-luciferase assays.

RESULTS

KLF9 was upregulated in lung tissues of COPD mice. Inhibition of KLF9 alleviated airway inflammation, reduced intrapulmonary inflammatory cell infiltration, and repressed NLRP3 expression. KLF9 bound to the miR-494-3p promoter and increased miR-494-3p expression, and miR-494-3p negatively regulated PTEN expression. miR-494-3p overexpression or Nigericin treatment reversed KLF9 knockdown-driven repression of NLRP3 inflammasome and inflammation.

CONCLUSION

KLF9 bound to the miR-494-3p promoter and repressed PTEN expression, thereby facilitating NLRP3 inflammasome-mediated inflammation.

Occupational quartz and particle exposure affect systemic levels of inflammatory markers related to inflammasome activation and cardiovascular disease

BACKGROUND

The inflammatory responses are central components of diseases associated with particulate matter (PM) exposure, including systemic diseases such as cardiovascular diseases (CVDs). The aim of this study was to determine if exposure to PM, including respirable dust or quartz in the iron foundry environment mediates systemic inflammatory responses, focusing on the NLRP3 inflammasome and novel or established inflammatory markers of CVDs.

METHODS

The exposure to PM, including respirable dust, metals and quartz were determined in 40 foundry workers at two separate occasions per worker. In addition, blood samples were collected both pre-shift and post-shift and quantified for inflammatory markers. The respirable dust and quartz exposures were correlated to levels of inflammatory markers in blood using Pearson, Kendall τ and mixed model statistics. Analyzed inflammatory markers included: 1) general markers of inflammation, including interleukins, chemokines, acute phase proteins, and white blood cell counts, 2) novel or established inflammatory markers of CVD, such as growth/differentiation factor-15 (GDF-15), CD40 ligand, soluble suppressor of tumorigenesis 2 (sST2), intercellular/vascular adhesion molecule-1 (ICAM-1, VCAM-1), and myeloperoxidase (MPO), and 3) NLRP3 inflammasome-related markers, including interleukin (IL)-1β, IL-18, IL-1 receptor antagonist (IL-1Ra), and caspase-1 activity.

RESULTS

The average respirator adjusted exposure level to respirable dust and quartz for the 40 foundry workers included in the study was 0.65 and 0.020 mg/m³, respectively. Respirable quartz exposure correlated with several NLRP3 inflammasome-related markers, including plasma levels of IL-1β and IL-18, and several caspase-1 activity measures in monocytes, demonstrating a reverse relationship. Respirable dust exposure mainly correlated with non-inflammasome related markers like CXCL8 and sST2.

CONCLUSIONS

The finding that NLRP3 inflammasome-related markers correlated with PM and quartz exposure suggest that this potent inflammatory cellular mechanism indeed is affected even at current exposure levels in Swedish iron foundries. The results highlight concerns regarding the safety of current exposure limits to respirable dust and quartz, and encourage continuous efforts to reduce exposure in dust and quartz exposed industries.

Tanshinone increases Hemopexin expression in lung cells and macrophages to protect against cigarette smoke-induced COPD and enhance antiviral responses

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease, while respiratory infections can elicit exacerbations in COPD patients to mediate increased mortality. Administration of Tanshinones (TS) derivatives has been demonstrated to protect against cigarette smoking (CS) and lipopolysaccharide (LPS)-induced COPD progression. However, the underlying molecular mechanisms and the roles of TS in mitigating the severity of viral-mediated exacerbations of COPD have not been elucidated. Here, we found that TS treatments significantly attenuated lung function decline, inflammatory responses and oxidative stress in CS and LPS-induced COPD mice. Subsequent RNA-seq analysis revealed significantly upregulated Hemopexin expression and enriched interferons (IFNs) signaling pathways in lung tissues of COPD mice upon TS treatments. Moreover, TS administration demonstrated Hemopexin-dependent beneficial roles in BEAS-2B lung cells and RAW264.7 macrophages, which was associated with the suppression of oxidative stress and ERK, NF-κB, and NLRP3 inflammasome signaling pathways-mediated inflammation. Furthermore, TS promoted IFN signaling and rescued impaired antiviral responses in CS and LPS-exposed lung cells that were infected by influenza virus. Notably, hemopexin over-expression in lung cells and macrophages recapitulated the pharmacological activities of TS. Taken together, these results indicate that TS administration is a promising and potential therapeutic strategy for treating COPD and preventing COPD exacerbations.

SIRT1 as a Potential Therapeutic Target for Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common, preventable, and treatable disease characterized by irreversible airflow obstruction and lung function decline. It is well established that COPD represents a major cause of morbidity and mortality globally. Due to the substantial economic and social burdens associated with COPD, it is necessary to discover new targets and develop novel beneficial therapies. Although the pathogenesis of COPD is complex and remains to be robustly elucidated, numerous studies have shown that oxidative stress, inflammatory responses, cell apoptosis, autophagy, and aging are involved in the pathogenesis of COPD. Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase belonging to the silent information regulator 2 (Sir2) family. Multiple studies have indicated that SIRT1 plays an important role in oxidative stress, apoptosis, inflammation, autophagy, and cellular senescence, which contributes to the pathogenesis and development of COPD. This review aimed to discuss the functions and mechanisms of SIRT1 in the progression of COPD and concluded that SIRT1 activation might be a potential therapeutic strategy for COPD.

Systemic Inflammation is Associated with Cardiometabolic Risk Factors and Clinical Outcomes

Purpose

Assessing an individual's systemic inflammatory state is vital to understand inflammation's role in cardiometabolic diseases and identify those at the greatest risk of disease. We generated global inflammation scores and investigated their associations with cardiometabolic risk factors and adverse outcomes.

Patients and Methods

Aggregate Inflammation Scores (AIS) and Principal Component Analysis (PCA) scores were generated for 7287 Framingham Heart Study participants using up to 26 inflammation-related proteins, with higher scores reflecting a pro-inflammatory milieu. Multivariable regression and proportional hazards analyses were conducted to investigate the associations of inflammation with cardiometabolic risk factors and outcomes. The primary outcomes for cross-sectional analyses included age, cigarette smoking, fasting lipid and glucose levels, blood pressure, body mass index (BMI), and hypertension, diabetes, and obesity. For prospective analyses, new-onset hypertension, diabetes, obesity, cardiovascular disease and all-cause mortality were investigated.

Results

Higher inflammation scores were associated with smoking and older age, higher BMI, systolic blood pressure, lipids, and glucose levels, and with greater odds of hypertension and diabetes after adjusting for age, sex, cohort, and BMI (all p < 0.001). Higher baseline scores were associated with greater odds of new-onset hypertension after adjusting for traditional risk factors (OR [95% CI] per one standard deviation [1-SD] increase, AIS: 1.33 [1.21-1.47], PCA score: 1.26 [1.12-1.42], p < 0.001). The AIS also was associated with new-onset diabetes (1.32 [1.14-1.52], p < 0.001). Proportional hazards analyses revealed greater risk of new-onset cardiovascular disease events and all-cause mortality (HR [95% CI] per 1-SD, AIS: 1.25 [1.14-1.37] and 1.32 [1.23-1.42], PCA score: 1.22 [1.13-1.33] and 1.40 [1.31-1.49], p < 0.001).

Conclusion

Global inflammation scores encompassing an array of pro- and anti-inflammatory proteins and pathways may enhance risk assessment for cardiometabolic diseases. The AIS and PCA scores provide further opportunities to investigate the mechanisms of inflammation-related risk of disease.

Pyroptosis and respiratory diseases: A review of current knowledge

Pyroptosis is a relatively newly discovered programmed cell death accompanied by an inflammatory response. In the classical view, pyroptosis is mediated by caspases-1,-4,-5,-11 and executed by GSDMD, however, recently it was demonstrated that caspase-3 and-8 also participate in the process of pyroptosis, by cleaving GSDMD/E and GSDMD respectively. Different from autophagy and apoptosis, many pores are formed on the cell membrane during pyroptosis, which makes the cell membrane lose its integrity, eventually leading to the release of cytokines interleukin(IL)-1β and IL-18. When the body is infected with pathogens or exposed to some stimulations, pyroptosis could play an immune defense role. It is found that pyroptosis exists widely in infectious and inflammatory respiratory diseases such as acute lung injury, bronchial dysplasia, chronic obstructive pulmonary disease, and asthma. Excessive pyroptosis may accompany airway inflammation, tissue injury, and airway damage, and induce an inflammatory reaction, leading to more serious damage and poor prognosis of respiratory diseases. This review summarizes the relationship between pyroptosis and related respiratory diseases.

HDAC3 Inhibition Alleviates High-Glucose-Induced Retinal Ganglion Cell Death through Inhibiting Inflammasome Activation

Purpose

The exact effects of histone deacetylase 3 (HDAC3) inhibition in DR related retinal ganglion cells (RGCs) death remained unclear. This study is aimed at detecting the influence of HDAC3 on the high-glucose-induced retinal ganglion cell death.

Methods

The retinal HDAC3 expression in DR of different time points was analyzed by immunohistochemical assay and western blot. Besides, the expression of HDAC3 and both retinal thickness and RGC loss were analyzed. The effects of HDAC3 inhibitor on cell viability, oxidative stress, and apoptosis in high-glucose- (HG-) treated RGCs were analyzed. Both inflammatory and antioxidative factors were detected by ELISA.

Results

Advanced effects of HDAC3 inhibition on the expression of NLRP3 inflammasome were detected using western blots. High HDAC3 expression was detected only in the late DR mice (4 months of diabetes duration) but not early DR mice (2 months of diabetes duration). The immunohistochemical assay showed that HDAC3 expression was correlated with both retinal thickness and RCG contents. HDAC3 inhibitor significantly protected the HG-treated RGCs from damaged cell viability, severe apoptosis, and oxidative stress. Advanced pathway analyses showed that HDAC3 inhibition inactivated NLRP3 inflammasome and thus alleviated retinal inflammation. Conclusion. In conclusion, HDAC3 was involved in RGC loss and thus promoted the progression of neurodegeneration of DR. Besides, HDAC3 inhibitor demonstrated protective effects in neurodegeneration in DR through downregulation of NLRP3 activity. The effects of HDAC3 inhibitor in DR management should be confirmed in clinical trials.

SARS-CoV-2: The Monster Causes COVID-19

Coronaviruses are viruses whose particles look like crowns. SARS-CoV-2 is the seventh member of the human coronavirus family to cause COVID-19 which is regarded as a once-in-a-century pandemic worldwide. It holds has the characteristics of a pandemic, which has broy -55ught many serious negative impacts to human beings. It may take time for humans to fight the pandemic. In addition to humans, SARS-CoV-2 also infects animals such as cats. This review introduces the origins, structures, pathogenic mechanisms, characteristics of transmission, detection and diagnosis, evolution and variation of SARS-CoV-2. We summarized the clinical characteristics, the strategies for treatment and prevention of COVID-19, and analyzed the problems and challenges we face.

Endothelial Microparticles Derived from Primary Pulmonary Microvascular Endothelial Cells Mediate Lung Inflammation in Chronic Obstructive Pulmonary Disease by Transferring microRNA-126

Background

Extracellular vesicles (EVs) are considered to new types of intercellular communication media, and microRNA is one of the most common transferring components of EVs. This study aimed to explore the potential role of endothelial microparticles (EMPs) derived from primary pulmonary microvascular endothelial cells in regulating lung inflammation of chronic obstructive pulmonary disease (COPD) through transferring microRNA-126 (miR-126).

Methods

EMPs generated from primary pulmonary microvascular endothelial cells were isolated by gradient centrifugation and characterized by transmission electron microscopy, flow cytometry and Western blotting. EMPs were treated to in vitro and in vivo COPD models induced by cigarette smoke extract (CSE). miR-126 mimics or inhibitors were transfected into EMPs by calcium chloride. Pathological changes of lung tissue, mRNA and protein levels of inflammation-related factors were measured to explore the effect of EMPs transferring miR-126 on CSE-induced inflammation.

Results

Both in vitro and in vivo studies demonstrated that mRNA and protein levels of inflammation-related factors were significantly increased in COPD group, while EMPs could dramatically reverse these increases. In vitro, overexpression of miR-126 in EMPs decreased HMGB1 expression and magnified the decreasing effect of EMPs on inflammation-related factors.

Conclusion

The present study reveals that EMPs are capable of alleviating lung inflammation and transferring miR-126 can magnify the anti-inflammatory effect of EMPs, which may provide a novel therapeutic alternative for COPD.

Involvement of the Innate Immune System in the Pathogenesis of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common, socially significant disease characterized by progressive airflow limitation due to chronic inflammation in the bronchi. Although the causes of COPD are considered to be known, the pathogenesis of the disease continues to be a relevant topic of study. Mechanisms of the innate immune system are involved in various links in the pathogenesis of COPD, leading to persistence of chronic inflammation in the bronchi, their bacterial colonization and disruption of lung structure and function. Bronchial epithelial cells, neutrophils, macrophages and other cells are involved in the development and progression of the disease, demonstrating multiple compromised immune mechanisms.