Although smoking is the most important and modifiable cause of chronic obstructive pulmonary disease (COPD), other risk factors including asthma and tuberculosis (TB) are also associated. It is common for COPD patients to have more than one of these risk factors. The aims of this study were to determine the prevalence of airflow limitation (FEV1/FVC<0.7) according to the risk factors and to investigate their impact and interaction in airflow limitation.

Chronic obstructive pulmonary disease is characterized by emphysema, chronic bronchitis, and small airway remodeling. The alveolar destruction associated with emphysema cannot be repaired by current clinical practices. Stem cell therapy has been successfully used in animal models of cigarette smoke- and elastase-induced emphysema. However, the optimal dose of mesenchymal stem cells (MSCs) for the most effective therapy has not yet been determined. It is vital to determine the optimal dose of MSCs for clinical application in emphysema cases.

This cohort study of patients with chronic obstructive pulmonary disease (COPD) was performed to evaluate the status of inhaled corticosteroid (ICS) prescriptions following the 2017 revision of the Global Initiative for Chronic Obstructive Lung Disease guidelines.

Hepatic sinusoid, the smallest vessel in the liver, plays important roles in hepatic microcirculation. Although the structure of the hepatic sinusoids affects diverse functions of the liver, little is known about morphological alterations in the sinusoids under pathological conditions. In this study, we show that the structure of hepatic sinusoids can be identified three-dimensionally in normal and carbon tetrachloride-injured mouse liver, using the absorption mode of synchrotron radiation micro-computed tomography. We observed that the hepatic sinusoidal structure on tomographic slice images was similar to that on histological images of normal and acutely injured mice. Moreover, centrilobular necrosis and structural alterations of the sinusoids in the necrotic region were detectable on tomographic slice and volume-rendered images of the acutely injured mice. Furthermore, quantitative analyses on 3D volume-rendered images of the injured sinusoid revealed decrease in the volume of the sinusoid and connectivity of the sinusoidal network. Our results suggest that the use of synchrotron radiation micro-computed tomography may improve our understanding of the pathogenesis of hepatic diseases by detecting the hepatic sinusoids and their alterations in three-dimensional structures of the damaged liver.

Escherichia coli, as one of the gut microbiota, can evoke severe inflammatory diseases including peritonitis and sepsis. Gram-negative bacteria including E. coli constitutively release nano-sized outer membrane vesicles (OMVs). Although E. coli OMVs can induce the inflammatory responses without live bacteria, the effect of E. coli OMVs in vivo on endothelial cell function has not been previously elucidated. In this study, we show that bacteria-free OMVs increased the expression of endothelial intercellular adhesion molecule-1 (ICAM-1), E-selectin and vascular cell adhesion molecule-1, and enhanced the leukocyte binding on human microvascular endothelial cells in vitro. Inhibition of NF-κB and TLR4 reduced the expression of cell adhesion molecules in vitro. OMVs given intraperitoneally to the mice induced ICAM-1 expression and neutrophil sequestration in the lung endothelium, and the effects were reduced in ICAM-1(-/-) and TLR4(-/-) mice. When compared to free lipopolysaccharide, OMVs were more potent in inducing both ICAM-1 expression as well as leukocyte adhesion in vitro, and ICAM-1 expression and neutrophil sequestration in the lungs in vivo. This study shows that OMVs potently up-regulate functional cell adhesion molecules via NF-κB- and TLR4-dependent pathways, and that OMVs are more potent than free lipopolysaccharide.

Immunotherapy was introduced 100 years ago and has a unique role in the treatment of allergic diseases in that only immunotherapy can induce long-term immunological tolerance. However, only a few mouse models of immunotherapy have been developed so far.

Chronic obstructive pulmonary disease (COPD) is responsible for significant morbidity and mortality worldwide. We evaluated the characteristics of stable COPD patients in the pulmonology clinics of seven Asian cities and also evaluated whether the exposure to biomass fuels and dusty jobs were related to respiratory symptoms, airflow limitation, and quality of life in the COPD patients.

Emerging evidence has suggested that the gut microbiota contribute to brain dysfunction, including pathological symptoms of Alzheimer disease (AD). Microbiota secrete membrane vesicles, also called extracellular vesicles (EVs), which contain bacterial genomic DNA fragments and other molecules and are distributed throughout the host body, including blood. In the present study, we investigated whether bacteria-derived EVs in blood are useful for metagenome analysis in an AD mouse model. Sequence readings of variable regions of 16S rRNA genes prepared from blood EVs in Tg-APP/PS1 mice allowed us to identify over 3,200 operational taxonomic units corresponding to gut microbiota reported in previous studies. Further analysis revealed a distinctive microbiota landscape in Tg-APP/PS1 mice, with a dramatic alteration in specific microbiota at all taxonomy levels examined. Specifically, at the phylum level, the occupancy of p_Firmicutes increased, while the occupancy of p_Proteobacteria and p_Bacteroidetes moderately decreased in Tg-APP/PS1 mice. At the genus level, the occupancy of g_Aerococcus, g_Jeotgalicoccus, g_Blautia, g_Pseudomonas and unclassified members of f_Clostridiale and f_Ruminococcaceae increased, while the occupancy of g_Lactobacillus, unclassified members of f_S24-7, and g_Corynebacterium decreased in Tg-APP/PS1 mice. A number of genus members were detected in Tg-APP/PS1 mice, but not in wild-type mice, while other genus members were detected in wild-type mice, but lost in Tg-APP/PS1 mice. The results of the present study suggest that the bodily microbiota profile is altered in Tg-APP/PS1 mice, and that blood EVs are useful for the metagenome analysis of bodily microbiota in AD.

Mesenchymal stem cells (MSCs) effectively reduce airway inflammation and regenerate the alveolus in cigarette- and elastase-induced chronic obstructive pulmonary disease (COPD) animal models. The effects of stem cells are thought to be paracrine and immune-modulatory because very few stem cells remain in the lung one day after their systemic injection, which has been demonstrated previously. In this report, we analyzed the gene expression profiles to compare mouse lungs with chronic exposure to cigarette smoke with non-exposed lungs. Gene expression profiling was also conducted in a mouse lung tissue with chronic exposure to cigarette smoke following the systemic injection of human cord blood-derived mesenchymal stem cells (hCB-MSCs). Globally, 834 genes were differentially expressed after systemic injection of hCB-MSCs. Seven and 21 genes, respectively, were up-and downregulated on days 1, 4, and 14 after HCB-MSC injection. The Hbb and Hba, genes with oxygen transport and antioxidant functions, were increased on days 1 and 14. A serine protease inhibitor was also increased at a similar time point after injection of hCB-MSCs. Gene Ontology analysis indicated that the levels of genes related to immune responses, metabolic processes, and blood vessel development were altered, indicating host responses after hCB-MSC injection. These gene expression changes suggest that MSCs induce a regeneration mechanism against COPD induced by cigarette smoke. These analyses provide basic data for understanding the regeneration mechanisms promoted by hCB-MSCs in cigarette smoke-induced COPD.

Gut microbiota play a role in regulating mental disorders, but the mechanism by which gut microbiota regulate brain function remains unclear. Gram negative and positive gut bacteria release membrane-derived extracellular vesicles (EVs), which function in microbiota-host intercellular communication. In the present study, we investigated whether Lactobacillus plantarum derived EVs (L-EVs) could have a role in regulating neuronal function and stress-induced depressive-like behaviors. HT22 cells treated with the stress hormone glucocorticoid (GC; corticosterone) had reduced expression of Bdnf and Sirt1, whereas L-EV treatment reversed GC-induced decreased expression of Bdnf and Sirt1. The siRNA-mediated knockdown of Sirt1 in HT22 cells decreased Bdnf4, a splicing variant of Bdnf, and Creb expression, suggesting that Sirt1 plays a role in L-EV-induced increase of BDNF and CREB expression. Mice exposed to restraint for 2-h daily for 14 days (CRST) exhibited depressive-like behaviors, and these CRST-treated mice had reduced expression of Bdnf and Nt4/5 in the hippocampus. In contrast, L-EV injection prior to each restraint treatment blocked the reduced expression of Bdnf and Nt4/5, and stress-induced depressive-like behaviors. Furthermore, L-EV treatment in CRST-treated mice also rescued the reduced expression of Bdnf, and blocked stress-induced depressive-like behaviors. These results suggest that Lactobacillus derived EVs can change the expression of neurotropic factors in the hippocampus and afford antidepressant-like effects in mice with stress-induced depression.

Colorectal cancer (CRC) is the most common type cancers in the world. CRC occurs sporadically in the majority of cases, indicating the predominant cause of the disease are environmental factors. Diet-induced changes in gut-microbiome are recently supposed to contribute on epidemics of CRC. This study was aimed to investigate the association of metagenomics and metabolomics in gut extracellular vesicles (EVs) of CRC and healthy subjects. A total of 40 healthy volunteers and 32 patients with CRC were enrolled in this study. Metagenomic profiling by sequencing 16 S rDNA was performed for assessing microbial codiversity. We explored the small molecule metabolites using gas chromatography-time-of-flight mass spectrometry. In total, stool EVs were prepared from 40 healthy volunteers and 32 patients with CRC. Metagenomic profiling demonstrated that bacterial phyla, particularly of Firmicutes and Proteobacteria, were significantly altered in patients with colorectal cancer. Through metabolomics profiling, we determined seven amino acids, four carboxylic acids, and four fatty acids; including short-chain to long chain fatty acids that altered in the disease group. Binary logistic regression was further tested to evaluate the diagnostic performance. In summary, the present findings suggest that gut flora dysbiosis may result in alternation of amino acid metabolism, which may be correlated with the pathogenesis of CRC.

Cysteinyl leukotriene (cysLT) overproduction and eosinophil activation are hallmarks of aspirin-exacerbated respiratory disease (AERD). However, pathogenic mechanisms of AERD remain to be clarified. Here, we aimed to find the significance of transforming growth factor beta 1 (TGF-β1) in association with cysteinyl leukotriene E4 (LTE4) production, leading to eosinophil degranulation. To evaluate levels of serum TGF-β1, first cohort enrolled AERD (n = 336), ATA (n = 442) patients and healthy control subjects (HCs, n = 253). In addition, second cohort recruited AERD (n = 34) and ATA (n = 25) patients to investigate a relation between levels of serum TGF-β1 and urinary LTE4. The function of TGF-β1 in LTE4 production was further demonstrated by ex vivo (human peripheral eosinophils) or in vivo (BALB/c mice) experiment. As a result, the levels of serum TGF-β1 were significantly higher in AERD patients than in ATA patients or HCs (P = .001; respectively). Moreover, levels of serum TGF-β1 and urinary LTE4 had a positive correlation (r = 0.273, P = .037). In the presence of TGF-β1, leukotriene C4 synthase (LTC4S) expression was enhanced in peripheral eosinophils to produce LTE4, which sequentially induced eosinophil degranulation via the p38 pathway. When mice were treated with TGF-β1, significantly induced eosinophilia with increased LTE4 production in the lung tissues were noted. These findings suggest that higher levels of TGF-β1 in AERD patients may contribute to LTE4 production via enhancing LTC4S expression which induces eosinophil degranulation, accelerating airway inflammation.

Emphysema is an important feature of chronic obstructive pulmonary disease (COPD). Genetic factors likely affect emphysema pathogenesis, but this question has predominantly been studied in those of European ancestry. In this study, we sought to determine genetic components of emphysema severity and characterize the potential function of the associated loci in Korean population. We performed a genome-wide association study (GWAS) on quantitative emphysema in subjects with or without COPD from two Korean COPD cohorts. We investigated the functional consequences of the loci using epigenetic annotation and gene expression data. We also compared our GWAS results with an epigenome-wide association study and previous differential gene expression analysis. In total, 548 subjects (476 [86.9%] male) including 514 COPD patients were evaluated. We identified one genome-wide significant SNP (P < 5.0 × 10-8), rs117084279, near PIBF1. We identified an additional 57 SNPs (P < 5.0 × 10-6) associated with emphysema in all subjects, and 106 SNPs (P < 5.0 × 10-6) in COPD patients. Of these candidate SNPs, 2 (rs12459249, rs11667314) near CYP2A6 were expression quantitative trait loci in lung tissue and a SNP (rs11214944) near NNMT was an expression quantitative trait locus in whole blood. Of note, rs11214944 was in linkage disequilibrium with variants in enhancer histone marks in lung tissue. Several genes near additional SNPs were identified in our previous EWAS study with nominal level of significance. We identified a novel SNP associated with quantitative emphysema on CT. Including the novel SNP, several candidate SNPs in our study may provide clues to the genetic etiology of emphysema in Asian populations. Further research and validation of the loci will help determine the genetic factors for the development of emphysema.

Although mounting evidence suggests that the microbiome has a tremendous influence on intractable disease, the relationship between circulating microbial extracellular vesicles (EVs) and respiratory disease remains unexplored. Here, we developed predictive diagnostic models for COPD, asthma, and lung cancer by applying machine learning to microbial EV metagenomes isolated from patient serum and coded by their accumulated taxonomic hierarchy. All models demonstrated high predictive strength with mean AUC values ranging from 0.93 to 0.99 with various important features at the genus and phylum levels. Application of the clinical models in mice showed that various foods reduced high-fat diet-associated asthma and lung cancer risk, while COPD was minimally affected. In conclusion, this study offers a novel methodology for respiratory disease prediction and highlights the utility of serum microbial EVs as data-rich features for noninvasive diagnosis.

The study evaluated the efficacy of ID-JPL934, a probiotic preparation containing Lactobacillus johnsonii IDCC 9203, Lactobacillus plantarum IDCC 3501 and Bifidobacterium lactis IDCC 4301, in relieving lower gastrointestinal symptoms. A total of 112 subjects with lower gastrointestinal symptoms were consecutively enrolled. They were randomized into either ID-JPL934 administration group or placebo group. Bristol stool form, stool frequency, and abnormal bowel movement symptoms were recorded at baseline and week 2, 6, and 8. Primary endpoint was improvement in overall symptoms at week 8. Fecal samples were collected to measure the probiotic levels in feces using quantitative polymerase chain reaction (qPCR), and to perform metagenomic analysis of microbiome originating from bacteria-derived extracellular vesicles and bacterial cells via 16S rDNA sequencing. Of the 112 subjects, 104 (54 in ID-JPL934 group and 50 in placebo group) completed the entire study protocol. A higher relief of overall symptoms was found in ID-JPL934 group than in placebo group (p = 0.016). Among lower gastrointestinal symptoms, abdominal pain and bloating scores were more decreased in ID-JPL934 group than in placebo group (p < 0.05). The fecal microbiome profiles of the two groups did not differ. However, the qPCR analysis showed significant increase in the levels of Lactobacillus johnsonii and Bifidobacterium lactis in feces post-treatment in ID-JPL934 group than in placebo group (p < 0.05 by repeated measure ANOVA). In conclusion, ID-JPL934 is effective in relieving lower gastrointestinal symptoms. Exposure to ID-JPL934 may increase the abundance of Lactobacillus johnsonii and Bifidobacterium lactis in the gut.Trial registration: ClinicalTrials.gov number, NCT03395626.

Different patterns of bacterial communities have been reported in the airways and gastrointestinal tract of asthmatics when compared to healthy controls. However, the blood microbiome of asthmatics is yet to be investigated. Therefore, we aimed to determine whether a distinct serum microbiome is observed in asthmatics by metagenomic analysis of serum extracellular vesicles (EVs). We obtained serum from 190 adults with asthma and 260 healthy controls, from which EVs were isolated and analyzed. The bacterial composition of asthmatics was significantly different from that of healthy controls. Chao 1 index was significantly higher in the asthma group, while Shannon and Simpson indices were higher in the control group. At the phylum level, Bacteroidetes was more abundant in asthmatics, while Actinobacter, Verrucomicrobia, and Cyanobacteria were more abundant in healthy controls. At the genus level, 24 bacterial genera showed differences in relative abundance between asthmatics and controls, with linear discriminant analysis scores greater than 3. Further, in a diagnostic model based on these differences, a high predictive value with a sensitivity of 0.92 and a specificity of 0.93 was observed. In conclusion, we demonstrated distinct blood microbiome in asthma indicating the role of microbiome as a potential diagnostic marker of asthma.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease of unknown cause which leads to alveolar epithelial cell apoptosis followed by basement membrane disruption and accumulation of extracellular matrix, destroying the lung architecture. Oxidative stress is involved in the development of alveolar injury, inflammation, and fibrosis. Oxidative stress-mediated alveolar epithelial cell (AEC) apoptosis is suggested to be a key process in the pathogenesis of IPF. Therefore, the present study investigated whether grape seed proanthocyanidin extract (GSPE) could inhibit the development of pulmonary fibrosis via ameliorating epithelial apoptosis through the inhibition of oxidative stress. We found that GSPE significantly ameliorated the histological changes and the level of collagen deposition in bleomycin (BLM)-induced lungs. Moreover, GSPE attenuated lung inflammation by reducing the total number of cells in bronchoalveolar lavage (BAL) fluid and decreasing the expression of IL-6. We observed that the levels of H2O2 leading to oxidative stress were increased following BLM instillation, which significantly decreased with GSPE treatment both in vivo and in vitro. These findings showed that GSPE attenuated BLM-induced epithelial apoptosis in the mouse lung and A549 alveolar epithelial cell through the inhibition of oxidative stress. Furthermore, GSPE could attenuate mitochondrial-associated cell apoptosis via decreasing the Bax/Bcl-2 ratio. The present study demonstrates that GSPE could ameliorate bleomycin-induced pulmonary fibrosis in mice via inhibition of epithelial apoptosis through the inhibition of oxidative stress.

Maximal oxygen uptake (VO₂ max) is a useful index to assess exercise capacity. However, there is no reference value for Koreans. This study aimed to compare actual VO₂ max and predicted VO₂ max using exercise capacity equations in Korean subjects.

Early detection is crucial for improving the prognosis of gastric cancer, but there are no non-invasive markers for the early diagnosis of gastric cancer in real clinical settings. Recently, bacteria-derived extracellular vesicles (EVs) emerged as new biomarker resources. We aimed to evaluate the microbial composition in gastric cancer using bacteria-derived EVs and to build a diagnostic prediction model for gastric cancer with the metagenome data. Stool, urine, and serum samples were prospectively collected from 453 subjects (gastric cancer, 181; control, 272). EV portions were extracted from the samples for metagenome analysis. Differences in microbial diversity and composition were analyzed with 16S rRNA gene profiling, using the next-generation sequencing method. Biomarkers were selected using logistic regression models based on relative abundances at the genus level. The microbial composition of healthy groups and gastric cancer patient groups was significantly different in all sample types. The compositional differences of various bacteria, based on relative abundances, were identified at the genus level. Among the diagnostic prediction models for gastric cancer, the urine-based model showed the highest performance when compared to that of stool or serum. We suggest that bacteria-derived EVs in urine can be used as novel metagenomic markers for the non-invasive diagnosis of gastric cancer by integrating the liquid biopsy method and metagenome analysis.

While interest in developing the human microbiome as a biomarker for attention-deficit hyperactivity disorder (ADHD) is increasing, there has been limited exploration in utilizing urine samples. In this study, we analysed urine microbiome profiles by extracting 16S ribosomal DNA from purified bacteria-derived extracellular membrane vesicles obtained from urine samples. Sequencing libraries were constructed by amplifying V3-V4 hypervariable regions sequenced using Illumina MiSeq. Profiles of male Korean children and adolescents with ADHD (n = 33) were compared with healthy sex-matched controls (n = 39). Statistically controlling for age, we found decreased alpha diversity in the urine bacteria of the ADHD group, as evidenced by reduced Shannon and Simpson indices (p < 0.05), and significant differences in beta diversity between the two groups (p < 0.001). The phyla Firmicutes and Actinobacteriota, as well as the genera Ralstonia and Afipia, were relatively more abundant in the ADHD group. The phylum Proteobacteria and the genera Corynebacterium and Peptoniphilus were more abundant in the control group. Notably, the genus Afipia exhibited significant correlations with the Child Behavior Checklist Attention Problems score and DSM-oriented ADHD subscale. This study is the first to propose the urine microbiome as a potential biomarker for pediatric ADHD.