Project description:<p>Chronic obstructive pulmonary disease (COPD) is the third leading cause of death in the United States and the only leading cause of death that is steadily increasing in frequency. This project collected a set of extended pedigrees ascertained through subjects with severe, early-onset COPD. This study has enrolled subjects with severe COPD (forced expiratory volume in one second (FEV1) < 40% predicted) at an early age (< 53 years) without alpha-1 antitrypsin deficiency (a known Mendelian risk factor for COPD). Extended pedigrees are enrolled, primarily in New England, although some more geographically distant subjects have been included. This study has been used for epidemiological studies, familial aggregation analysis, linkage analysis, and candidate gene association analysis. Approximately 80 of the severe, early-onset COPD probands will undergo whole genome sequencing in this project with sequencing data available through dbGaP.</p> <p> <ul> <li>This third study release makes available VCF files derived from sequence aligned to genome build 38, in addition to those aligned to build 37 and available through study version 1. The samples in the b38 vs b37 VCF may also differ.</li> </ul> </p>
Project description:Chronic inflammatory and immune dysregulation are critical drivers in the development and progression of chronic obstructive pulmonary disease (COPD). Posttranslational modifications, such as glycosylation of Immunoglobulin G (IgG), modulates systemic inflammatory homeostasis. This study aims to profile plasma IgG glycopeptides (IgGPs) in COPD patients to uncover new insights into its pathogenesis and to identify novel biomarkers. Plasma IgG N-glycopeptides from 90 COPD patients, 45 clinical defined early COPD (CECOPD) patients and 90 healthy individuals were analyzed using an integrated platform that combines Fe3O4@PDA@DETA nanospheres enrichment with high-resolution mass spectrometry measurement. Correlations between IgG N-glycoforms and clinical parameters were assessed to explore underlying mechanisms of COPD progression. Disease-specific IgGPs were identified in both ECOPD and COPD cohorts. Notably, IgG glyco-pattern, rather than IgG levels, changed with disease progression. Early COPD patients showed decreased bisection and increased site-specific afucosylated galactosylation and fucosylation of IgG, indicating an anti-inflammatory state. In contrast, COPD patients gave increased inflammation, characterized by reduced galactosylation and sialylation. Interestingly, a subset of healthy controls displayed IgGPs patterns similar to early COPD, possibly reflecting the impact of substantial smoking exposure and associated immune responses. These findings suggest that plasma IgG glycosylation could serve as a potential biomarker for early COPD diagnosis, providing valuable insights into immune system changes during disease progression.
Project description:Methods: This study analyzed lung tissue sequencing data from early-stage COPD patients (GSE47460) and smoke-exposed mice. We employed Weighted Gene Co-Expression Network Analysis (WGCNA) and machine learning to identify potential pathogenic genes. Further analyses included single-cell sequencing from mice and COPD patients to identify gene expression in specific cell subgroups. Cell-chat and pseudo-temporal analyses were conducted, with findings validated in smoke-exposed mice. Additionally, Mendelian randomization (MR) was utilized to verify the relationship between candidate genes and lung function/COPD. Lastly, functional validation was performed in vitro in cell cultures. Results: "Machine learning analysis of 30 differentially expressed genes pinpointed 8 key genes, with CLEC5A identified as a potential pathogenic factor in early COPD. Bioinformatics suggested CLEC5A's role in macrophage-mediated inflammation in COPD. Two-sample Mendelian randomization linked CLEC5A SNPs with FEV1, FEV1/FVC, and emphysema/chronic bronchitis. In vitro, CLEC5A knockdown reduced inflammatory markers in macrophages. Conclusion: Our study identifies CLEC5A as a pivotal gene in early-stage COPD, contributing to its pathogenesis through pro-inflammatory mechanisms. This discovery offers insights for early diagnosis and treatment strategies in COPD, highlighting CLEC5A as a target for further research.
Project description:Rationale: Chronic obstructive pulmonary disease (COPD) is a prevalent respiratory disease lacking disease modifying treatment. The role of CXCL12/CXCR4 axis has been demonstrated in acute exacerbation of COPD. The interest of study early COPD has been recently pointed out. Objectives: To study the role of the CXCL12/CXCR4 axis in both human and mouse model of early COPD. Methods: Blood and lung tissue were obtained from both COPD patients and mice exposed to cigarette smoke (CS) for 10 weeks and intranasal instillations of polyinosinic–polycytidylic acid (poly(I:C)) to mimic exacerbations for 5 weeks. Measurements and Main Results: Exposed mice presented mild airway obstruction, peri-bronchial fibrosis and right heart remodeling. The level of CXCR4 expressing cells was increased in the blood of exposed mice, as well as in the blood of patients with mild COPD. Lung CXCL12 expression was higher both in exposed mice and COPD patients. The densities of fibrocytes expressing CXCR4 were increased in the blood and in the bronchial submucosa of exposed mice. Conditional inactivation of CXCR4 at adult stage as well as pharmacological inhibition of CXCR4 with plerixafor injections improved lung function and inflammation and protected against CS and poly-(I:C)-induced airway and cardiac remodeling. CXCR4-/- and plerixafor-treated mice also had reduced levels of CXCR4-expressing circulating cells and a lower density of peri-bronchial fibrocytes. Conclusions: We demonstrated that targeting CXCR4 has beneficial effects in an animal model of early COPD, and provide a framework to translate preclinical findings to clinical settings within a drug repurposing approach.