Association between the IL1B, IL1RN polymorphisms and COPD risk: a meta-analysis

Genetic Variants Associated with Chronic Obstructive Pulmonary Disease Risk: Cumulative Epidemiological Evidence from Meta-Analyses and Genome-Wide Association Studies

Background

Last two decades, many association studies on genetic variants and chronic obstructive pulmonary disease (COPD) risk have been published. But results from different studies are inconsistent. Therefore, we performed this article to systematically evaluate results from previous meta-analyses and genome-wide association studies (GWASs). Material and Methods. Firstly, we retrieved meta-analyses in PubMed, Embase, and China National Knowledge Infrastructure and GWASs in PubMed and GWAS catalog on or before April 7th, 2022. Then, data were extracted and screened. Finally, two main methods—Venice criteria and false-positive report probability test—were used to evaluate significant associations.

Results

As a result, eighty-eight meta-analyses and 5 GWASs were deemed eligible for inclusion. Fifty variants in 26 genes obtained from meta-analyses were significantly associated with COPD risk. Cumulative epidemiological evidence of an association was graded as strong for 10 variants in 8 genes (GSTM1, CHRNA, ADAM33, SP-D, TNF-α, VDBP, HMOX1, and HHIP), moderate for 6 variants in 5 genes (PI, GSTM1, ADAM33, TNF-α, and VDBP), and weak for 40 variants in 23 genes. Five variants in 4 genes showed convincing evidence of no association with COPD risk in meta-analyses. Additionally, 29 SNPs identified in GWASs were proved to be noteworthy based on the FPRP test.

Conclusion

In summary, more than half (52.38%) of genetic variants reported in previous meta-analyses showed no association with COPD risk. However, 13 variants in 9 genes had moderate to strong evidence for an association. This article can serve as a useful reference for further studies.

Identification of Potential Key Genes in the Pathogenesis of Chronic Obstructive Pulmonary Disease Through Bioinformatics Analysis

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease with high morbidity and mortality. The etiology of COPD is complex, and the pathogenesis mechanisms remain unclear. In this study, we used rat and human COPD gene expression data from our laboratory and the Gene Expression Omnibus (GEO) database to identify differentially expressed genes (DEGs) between individuals with COPD and healthy individuals. Then, protein–protein interaction (PPI) networks were constructed, and hub genes were identified. Cytoscape was used to construct the co-expressed network and competitive endogenous RNA (ceRNA) networks. A total of 198 DEGs were identified, and a PPI network with 144 nodes and 355 edges was constructed. Twelve hub genes were identified by the cytoHubba plugin in Cytoscape. Of these genes, CCR3, CCL2, COL4A2, VWF, IL1RN, IL2RA, and CCL13 were related to inflammation or immunity, or tissue-specific expression in lung tissue, and their messenger RNA (mRNA) levels were validated by qRT-PCR. COL4A2, VWF, and IL1RN were further verified by the GEO dataset GSE76925, and the ceRNA network was constructed with Cytoscape. These three genes were consistent with COPD rat model data compared with control data, and their dysregulation direction was reversed when the COPD rat model was treated with effective-component compatibility of Bufei Yishen formula III. This bioinformatics analysis strategy may be useful for elucidating novel mechanisms underlying COPD. We pinpointed three key genes that may play a role in COPD pathogenesis and therapy, which deserved to be further studied.

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

Chronic obstructive pulmonary disease (COPD) is an inflammatory lung disease characterized by chronic airway obstruction and emphysema. Accumulating studies have shown that the onset and development of COPD are related to an aberrant immune response induced by the dysregulation of a number of genetic and environmental factors, while the exact pathogenesis of this disease is not well defined. Emerging studies based on tests on samples from COPD patients, animal models, pharmacological and genetic data suggest that the NLR family pyrin domain containing 3 (NLRP3) inflammasome activation is required in the lung inflammatory responses in the development of COPD. Although the available clinical studies targeting the inflammasome effector cytokine, IL-1β, or IL-1 signaling do not show positive outcomes for COPD treatment, many alternative strategies have been proposed by recent emerging studies. Here, we highlight the recent progress in our understanding of the role of the NLRP3 inflammasome in COPD and propose possible future studies that may further elucidate the roles of the inflammasome in the pathogenesis or the intervention of this inflammatory lung disease.

miR-937 serves as an inflammatory inhibitor in cigarette smoke extract-induced human bronchial epithelial cells by targeting IL1B and regulating TNF-α/IL-17 signaling pathway

INTRODUCTION

This study aimed to elucidate the biological implication of miR-937 in cigarette smoke extract (CSE)-induced human bronchial epithelial (HBE) cells and to further investigate its possible regulatory mechanism.

METHODS

Public datasets were downloaded to identify differentially expressed genes and subjected to Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis in chronic obstructive pulmonary disease (COPD). Online prediction site and luciferase reporter assay were applied to determine the target correlation between miR-937 and IL1B. RT-qPCR, Western blot and Enzyme-Linked Immunosorbent Assays (ELISA) analyses were used to evaluate the expressions of indicated molecules. HBE cells were exposed with CSE (20 μg/mL) to construct the in vitro COPD model. Cell proliferation and apoptosis were measured through cell counting kit 8 and Annexin-V/propidium iodide (PI) staining assays.

RESULTS

IL1B was found to be up-regulated in COPD samples compared with healthy controls and had a high correlation with the TNF and IL-17 pathways according to the data from GSE57148. Moreover, IL1B was predicted to be a target of miR-937, and it was negatively regulated by miR-937. CSE treatment reduced the miR-937 expression, meanwhile decreased the HBE cells proliferation, enhanced cells apoptosis, and elevated the expression of IL-6, IL-17, and TNF-α. Moreover, in the CSE model, upregulation of miR-937 promoted cells viability, restrained cells apoptosis, and decreased levels of IL-6, IL-17, and TNF-α were noted, which could be abolished by overexpression IL1B. In contrast, inhibiting miR-937 impeded cells proliferation, promoted cells apoptosis and elevated levels of IL-6, IL-17 and TNF-α, which could be rescued by IL1B-knockdown in CSE-induced HBEs.

CONCLUSIONS

These findings suggest that miR-937 plays a protective role on the HBEs after CSE damage, which may be achieved via targeting IL1B and inhibiting the TNF-α/IL-17 signaling pathway.

Molecularly Distinct NLRP3 Inducers Mediate Diverse Ratios of Interleukin-1β and Interleukin-18 from Human Monocytes

Inflammasomes cleave and activate interleukin- (IL-) 1β and IL-18 which have both shared and unique biological functions. IL-1β is an important mediator of the acute phase response to infections and tissue damage, whereas IL-18 takes part in activation and tailoring of the adaptive immune response. While IL-1β has served as the prototypic indicator of inflammasome activation, few studies have compared the potential differences in IL-1β and IL-18 production during inflammasome activation. Since these cytokines partake in different immune pathways, the involvement of inflammasome activity in different conditions needs to be described beyond IL-1β production alone. To address a potential heterogeneity in inflammasome functionality, ATP, chitosan, or silica oxide (SiO₂) were used to induce NLRP3 inflammasome activation in THP-1 cells and the subsequent outcomes were quantified. Despite using doses of the inflammasome inducers yielding similar release of IL-1β, SiO₂-stimulated cells showed a lower concentration of released IL-18 compared to ATP and chitosan. Hence, the cells stimulated with SiO₂ responded with a distinctly different IL-18 : IL-1β ratio. The difference in the IL-18 : IL-1β ratio for SiO₂ was constant over different doses. While all downstream responses were strictly dependent on a functional NLRP3 inflammasome, the differences did not depend on the level of gene expression, caspase-1 activity, or pyroptosis. We suggest that the NLRP3 inflammasome response should be considered a dynamic process, which can be described by taking the ratio between IL-1β and IL-18 into account and moving away from an on/off perspective of inflammasome activation.

Association between chronic obstructive pulmonary disease and interleukins gene variants: A systematic review and meta-analysis

Interleukins are cytokines involved in systemic inflammation and immune system regulation. Many studies have investigated the association between common genetic variations in interleukin-coding genes and COPD susceptibility. In this study, a systematic review and meta-analysis was performed to evaluate the association between interleukin gene variations and COPD pathogenesis. Association studies were retrieved from PubMed and Google Scholar databases using the standard systematic search strategy. A total of 26 different studies evaluating eight polymorphisms in four interleukin genes were included in this study. In overall comparisons, IL1β-rs16944, -rs1143627, -rs1143634, IL13-rs20541 polymorphisms were found not to be associated with the increased risk for developing COPD. However, IL1RN-rs2234663 and IL13-rs1800925 showed a strong association with COPD. We showed that the CC genotype carriers of the IL6-rs1800795 are at significantly higher risk of developing COPD (OR = 1.31, 95% CI: 1.04-1.64, P = 0.01) compared to GG carriers. In case of IL6-rs1800796, individuals with CC and CG genotypes showed a lower risk to develop COPD (OR = 0.46, 95%CI: 0.32-0.66, P > 0.00). This updated meta-analysis strongly supports the association of IL1RN-rs2234663, IL6-rs1800795, -rs1800795 and IL13-rs1800925 variants with COPD.

Genetic Association of Pulmonary Surfactant Protein Genes, SFTPA1, SFTPA2, SFTPB, SFTPC, and SFTPD With Cystic Fibrosis

Surfactant proteins (SP) are involved in surfactant function and innate immunity in the human lung. Both lung function and innate immunity are altered in CF, and altered SP levels and genetic association are observed in Cystic Fibrosis (CF). We hypothesized that single nucleotide polymorphisms (SNPs) within the SP genes associate with CF or severity subgroups, either through single SNP or via SNP-SNP interactions between two SNPs of a given gene (intragenic) and/or between two genes (intergenic). We genotyped a total of 17 SP SNPs from 72 case-trio pedigree (SFTPA1 (5), SFTPA2 (4), SFTPB (4), SFTPC (2), and SFTPD (2)), and identified SP SNP associations by applying quantitative genetic principles. The results showed (a) Two SNPs, SFTPB rs7316 (p = 0.0083) and SFTPC rs1124 (p = 0.0154), each associated with CF. (b) Three intragenic SNP-SNP interactions, SFTPB (rs2077079, rs3024798), and SFTPA1 (rs1136451, rs1059057 and rs4253527), associated with CF. (c) A total of 34 intergenic SNP-SNP interactions among the 4 SP genes to be associated with CF. (d) No SNP-SNP interaction was observed between SFTPA1 or SFTPA2 and SFTPD. (e) Equal number of SNP-SNP interactions were observed between SFTPB and SFTPA1/SFTPA2 (n = 7) and SP-B and SFTPD (n = 7). (f) SFTPC exhibited significant SNP-SNP interactions with SFTPA1/SFTPA2 (n = 11), SFTPB (n = 4) and SFTPD (n = 3). (g) A single SFTPB SNP was associated with mild CF after Bonferroni correction, and several intergenic interactions that are associated (p < 0.01) with either mild or moderate/severe CF were observed. These collectively indicate that complex SNP-SNP interactions of the SP genes may contribute to the pulmonary disease in CF patients. We speculate that SPs may serve as modifiers for the varied progression of pulmonary disease in CF and/or its severity.

Immune-related gene polymorphisms in pulmonary diseases

Between the DNA sequences of two randomly-selected human genomes, which consist of over 3 billion base pairs and twenty five thousand genes, there exists only 0.1% variation and 99.9% sequence identity. During the last couple of decades, extensive genome-wide studies have investigated the association between single-nucleotide polymorphisms (SNPs), the most common DNA variations, and susceptibility to various diseases. Because the immune system's primary function is to defend against myriad infectious agents and diseases, the large number of people who escape serious infectious diseases underscores the tremendous success of this system at this task. In fact, out of the third of the global human population infected with Mycobacterium tuberculosis during their lifetime, only a few people develop active disease, and a heavy chain smoker may inexplicably escape all symptoms of chronic obstructive pulmonary disease (COPD), lung cancer, and other smoke-associated lung diseases. This may be attributable to the genetic makeup of the individual(s), including their SNPs, which provide some resistance to the disease. Pattern recognition receptors (PRRs), transcription factors, cytokines and chemokines all play critical roles in orchestrating immune responses and their expression/activation is directly linked to human disease tolerance. Moreover, genetic variations present in the immune-response genes of various ethnicities may explain the huge differences in individual outcomes to various diseases and following exposure to infectious agents. The current review focuses on recent advances in our understanding of pulmonary diseases and the relationship of genetic variations in immune response genes to these conditions.

Pinellia ternata Attenuates Mucus Secretion and Airway Inflammation after Inhaled Corticosteroid Withdrawal in COPD Rats

Inhaled corticosteroids (ICS) are widely used to manage chronic obstructive pulmonary disease (COPD). However, withdrawal of ICS generally causes various adverse effects, warranting careful management of the ICS withdrawal. Pinellia ternata, a traditional Chinese herbal medicine, has been used to treat respiratory diseases in China for centuries. Here, we investigated its role in antagonizing ICS withdrawal-induced side effects, and explored the underlying mechanisms. The rat COPD model was established using a combination of passive cigarette smoking and intratracheal instillation of lipopolysaccharide (LPS). COPD rats were treated with saline or budesonide inhalation, or with budesonide inhalation followed by saline inhalation or Pinellia ternata gavage. The number of goblet cells and the level of mucin 5AC (MUC5AC) were enhanced by budesonide withdrawal. Pinellia ternata treatment significantly blocked these effects. Further, Pinellia ternata treatment reversed budesonide withdrawal-induced increase of interleukin 1[Formula: see text] (IL-1[Formula: see text] and tumor necrosis factor [Formula: see text] (TNF-[Formula: see text]) levels in bronchoalveolar lavage fluid (BALF). Extracellular signal-regulated kinase (ERK), but neither p38 nor c-Jun N-terminal kinase (JNK), was activated by budesonide withdrawal, and the activation was blocked by Pinellia ternata treatment. The MUC5AC expression was positively correlated with goblet cell number, IL-1[Formula: see text] and TNF-[Formula: see text] levels, and ERK activity. Pinellia ternata treatment protected the airway from ICS withdrawal-induced mucus hypersecretion and airway inflammation by inhibiting ERK activation. Pinellia ternata treatment may represent a novel therapeutic strategy to prevent ICS withdrawal-induced side effects in COPD patients.

Associations of interleukin-1 gene cluster polymorphisms with C-reactive protein concentration and lung function decline in smoking-induced chronic obstructive pulmonary disease

OBJECTIVE

We reported association of haplotypes formed by IL-1b (IL1B)-511C/T (rs16944) and a variable number of tandem repeats (rs2234663) in intron 3 of IL-1 receptor antagonist (IL1RN) with rate of lung function decline in smoking-induced COPD. The aim of current study was to further investigate this association.

METHODS

We genotyped an additional 19 polymorphisms in IL1 cluster (including IL1A, IL1B and IL1RN) in non-Hispanic whites who had the fastest (n = 268) and the slowest (n = 292) decline of FEV1% predicted in the same study. We also analyzed the association of all 21 polymorphisms with serum CRP levels.

RESULTS

None of 21 polymorphisms showed significant association with rate of decline of lung function or CRP levels after adjusting for multiple comparisons. Before adjusting for multiple comparisons, only IL1RN_19327 (rs315949) showed significant association with lung function decline (P = 0.03, additive model). The frequencies of genotypes containing the IL1RN_19327A allele were 71.9% and 62.2%, respectively in the fast and slow decline groups (P = 0.02, odds ratio = 1.6, 95% confidence interval = 1.1-2.3); the IL1B_5200 (rs1143633) and rs2234663 in IL1RN were associated with serum CRP levels (P=0.04 and 0.03, respectively).

CONCLUSIONS

No single marker was significantly associated with either rate of lung function decline or serum CRP levels.

Novel aspects of pathogenesis and regeneration mechanisms in COPD

Chronic obstructive pulmonary disease (COPD), a major cause of death and morbidity worldwide, is characterized by expiratory airflow limitation that is not fully reversible, deregulated chronic inflammation, and emphysematous destruction of the lungs. Despite the fact that COPD is a steadily growing global healthcare problem, the conventional therapies remain palliative, and regenerative approaches for disease management are not available yet. We aim to provide an overview of key reviews, experimental, and clinical studies addressing lung emphysema development and repair mechanisms published in the past decade. Novel aspects discussed herein include integral revision of the literature focused on lung microflora changes in COPD, autoimmune component of the disease, and environmental risk factors other than cigarette smoke. The time span of studies on COPD, including emphysema, chronic bronchitis, and asthmatic bronchitis, covers almost 200 years, and several crucial mechanisms of COPD pathogenesis are described and studied. However, we still lack the holistic understanding of COPD development and the exact picture of the time-course and interplay of the events during stable, exacerbated, corticosteroid-treated COPD states, and transitions in-between. Several generally recognized mechanisms will be discussed shortly herein, ie, unregulated inflammation, proteolysis/antiproteolysis imbalance, and destroyed repair mechanisms, while novel topics such as deviated microbiota, air pollutants-related damage, and autoimmune process within the lung tissue will be discussed more extensively. Considerable influx of new data from the clinic, in vivo and in vitro studies stimulate to search for novel concise explanation and holistic understanding of COPD nowadays.