DNA methylation in chronic obstructive pulmonary disease

Identification of genetic variants of the IL18R1 gene in association with COPD susceptibility

BACKGROUND

Although existing studies have identified some genetic loci associated with chronic obstructive pulmonary disease (COPD) susceptibility, many variants remain to be discovered. The aim of this study was to further explore the potential relationship between IL18R1 single nucleotide polymorphisms (SNPs) and COPD risk.

METHODS

Nine hundred and ninety-six subjects were recruited (498 COPD cases and 498 healthy controls). Five candidate SNPs of IL18R1 were selected and genotyped using MassARRAY iPLEX platform. Logistic regression analysis was performed to assess the association of these SNPs with COPD risk. Multifactor dimensionality reduction (MDR) software was applied to calculate the interaction of SNP-SNP on COPD risk.

RESULTS

IL18R1 rs9807989 (OR = 0.42, p < .001), rs3771166 (OR = 0.40, p < .001) and rs6543124 (OR = 0.44, p < .001) were associated with the reduced COPD risk, while rs2287037 (OR = 2.71, p < .001) and rs2058622 (OR = 2.06, p < .001) might be the risk-increasing factor for COPD occurrence in both the overall analysis and subgroup analysis (age, gender, drinking, and smoking). The best multi-locus model was the combination of rs2058622 and rs3771166.

CONCLUSION

Our study provided a reference and basis for investigating the association of IL18R1 polymorphisms with COPD risk.

DNA hypomethylation-mediated upregulation of GADD45B facilitates airway inflammation and epithelial cell senescence in COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease typically characterized by chronic airway inflammation, with emerging evidence highlighting the driving role of cellular senescence-related lung aging. Accelerated lung aging and inflammation mutually reinforce each other, creating a detrimental cycle that contributes to disease progression. Growth arrest and DNA damage-inducible (GADD45) family has been reported to involve in multiple biological processes, including inflammation and senescence. However, the role of GADD45 family in COPD remains elusive.

OBJECTIVES

To investigate the role and mechanism of GADD45 family in COPD pathogenesis.

METHODS

Expressions of GADD45 family were evaluated by bioinformatic analysis combined with detections in clinical specimens. The effects of GADD45B on inflammation and senescence were investigated via constructing cell model with siRNA transfection or overexpression lentivirus infection and animal model with Gadd45b knockout. Targeted bisulfite sequencing was performed to probe the influence of DNA methylation in GADD45B expression in COPD.

RESULTS

GADD45B expression was significantly increased in COPD patients and strongly associated with lung function, whereas other family members presented no changes. GADD45B upregulation was confirmed in mice exposed by cigarette smoke (CS) and HBE cells treated by CS extract as well. Moreover, experiments involving bidirectional modulation of GADD45B expression in HBE cells further substantiated its positive regulatory role in inflammatory response and cellular senescence. Mechanically, GADD45B-facilitated inflammation was directly mediated by p38 phosphorylation, while GADD45B interacted with FOS to promote cellular senescence in a p38 phosphorylation-independent manner. Furthermore, Gadd45b deficiency remarkably alleviated inflammation and senescence of lungs in CS-exposed mice, as well as improved emphysema and lung function. Eventually, in vivo and vitro experiments demonstrated that GADD45B overexpression was partially mediated by CS-induced DNA hypomethylation.

CONCLUSION

Our findings have shed light on the impact of GADD45B in the pathogenesis of COPD, thereby offering a promising target for intervention in clinical settings.

Effectiveness of Immunotherapy in Non-Small Cell Lung Cancer Patients with a Diagnosis of COPD: Is This a Hidden Prognosticator for Survival and a Risk Factor for Immune-Related Adverse Events?

The interplay between the immune system and chronic obstructive pulmonary disease (COPD) and non-small cell lung cancer (NSCLC) is complex and multifaceted. In COPD, chronic inflammation and oxidative stress can lead to immune dysfunction that can exacerbate lung damage, further worsening the respiratory symptoms. In NSCLC, immune cells can recognise and attack the cancer cells, which, however, can evade or suppress the immune response by various mechanisms, such as expressing immune checkpoint proteins or secreting immunosuppressive cytokines, thus creating an immunosuppressive tumour microenvironment that promotes cancer progression and metastasis. The interaction between COPD and NSCLC further complicates the immune response. In patients with both diseases, COPD can impair the immune response against cancer cells by reducing or suppressing the activity of immune cells, or altering their cytokine profile. Moreover, anti-cancer treatments can also affect the immune system and worsen COPD symptoms by causing lung inflammation and fibrosis. Immunotherapy itself can also cause immune-related adverse events that could worsen the respiratory symptoms in patients with COPD-compromised lungs. In the present review, we tried to understand the interplay between the two pathologies and how the efficacy of immunotherapy in NSCLC patients with COPD is affected in these patients.

Epigenetic Reprogramming Drives Epithelial Disruption in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) remains a major public health challenge that contributes greatly to mortality and morbidity worldwide. Although it has long been recognized that the epithelium is altered in COPD, there has been little focus on targeting it to modify the disease course. Therefore, mechanisms that disrupt epithelial cell function in patients with COPD are poorly understood. In this study, we sought to determine whether epigenetic reprogramming of the cell-cell adhesion molecule E-cadherin, encoded by the CDH1 gene, disrupts epithelial integrity. By reducing these epigenetic marks, we can restore epithelial integrity and rescue alveolar airspace destruction. We used differentiated normal and COPD-derived primary human airway epithelial cells, genetically manipulated mouse tracheal epithelial cells, and mouse and human precision-cut lung slices to assess the effects of epigenetic reprogramming. We show that the loss of CDH1 in COPD is due to increased DNA methylation site at the CDH1 enhancer D through the downregulation of the ten-eleven translocase methylcytosine dioxygenase (TET) enzyme TET1. Increased DNA methylation at the enhancer D region decreases the enrichment of RNA polymerase II binding. Remarkably, treatment of human precision-cut slices derived from patients with COPD with the DNA demethylation agent 5-aza-2'-deoxycytidine decreased cell damage and reduced air space enlargement in the diseased tissue. Here, we present a novel mechanism that targets epigenetic modifications to reverse the tissue remodeling in human COPD lungs and serves as a proof of concept for developing a disease-modifying target.

Impact of chronic obstructive pulmonary disease on the efficacy and safety of neoadjuvant immune checkpoint inhibitors combined with chemotherapy for resectable non-small cell lung cancer: a retrospective cohort study

BACKGROUND

Neoadjuvant immune checkpoint inhibitors(ICIs) combined with chemotherapy can improve non-small cell lung cancer(NSCLC) patients' pathological responses and show promising improvements in survival. Chronic obstructive pulmonary disease (COPD) is a systemic inflammatory disease, and its associated abnormal inflammatory response affects not only the immunotherapy efficacy but also immune-related adverse events. It remains unclear whether NSCLC patients with COPD can benefit from neoadjuvant ICIs combined with chemotherapy.

METHODS

A retrospective observational clinical study was conducted on 105 consecutive NSCLC patients receiving neoadjuvant ICIs combined with chemotherapy at the Department of Thoracic Surgery of Tianjin Chest Hospital between April 2020 and April 2023.

RESULTS

A total of 74 NSCLC patients were included in the study, including 30 patients with COPD and 44 patients without COPD. The percentage of patients with a pathological complete response (PCR) was higher in the COPD group than in the non-COPD group (43.3% vs. 20.5%, P = 0.042). Multivariate logistic regression analysis of factors associated with PCR showed that the adjusted odds ratio (OR) was statistically significant for presence of COPD (OR = 3.020, 95%CI: 1.042-8.757; P = 0.042). Major pathological response (66.7% vs. 50%, P = 0.155), R0 resection rate (96.7% vs.93.2%, P = 0.642), N2 lymph node downstaging(92.3% vs. 66.7%, P = 0.182) and objective response rate (70% vs. 63.6%, P = 0.57) were not significantly different between the groups. Progression-free survival(PFS) was not reached in the COPD group and 17 months (95%CI: 12.1-21.9) in the non-COPD group, with statistically significance (χ2 = 6.247, P = 0.012). Multivariate Cox's regression analysis showed that the adjusted hazard ratio (HRadj) was statistically significant for presence of COPD (HRadj = 0.321, 95%CI: 0.111-0.930; P = 0.036). The grade 3 and grade 4 adverse events in the COPD group were leukopenia (3.3%, 6.7%), neutropenia (3.3%, 6.7%), fatigue (6.7%, 0%), gastrointestinal reactions (3.3%, 0%), and hypothyroidism (3.3%, 0%). In the non-COPD group, the corresponding adverse events were leukopenia (6.8%, 6.8%), neutropenia (3.3%, 6.8%), fatigue (2.3%, 0%), gastrointestinal reactions (2.3%, 0%), and hypothyroidism (2.3%, 0%), respectively.

CONCLUSIONS

The present study indicates that the presence of COPD may improve PCR, prolong PFS, and have an acceptable safety profile in NSCLC patients receiving neoadjuvant ICIs combined with chemotherapy.

Sevoflurane with Low Concentration Decrease DNA Methylation on Chronic Obstructive Pulmonary Disease (COPD)-Related Gene Promoter in COPD Rat

Chronic obstructive pulmonary disease (COPD) is a difficult-to-cure disease that mainly affects the respiratory system. Inhaled anesthetic drug such as sevoflurane plays a controversial role in COPD by different concentration, but the underlying epigenetic mechanism remains unclear. Here, we prepared lipopolysaccharide (LPS)-induced COPD rat model, and isolated Alveolar type II (ATII) cells. We mainly focused DNA methylation on the promoter of COPD-related genes including Sftpa1, Napsa, Ca2, Sfta2, Lamp3, Wif1, Pgc, and Etv5. We observed COPD rat treated by sevoflurane with low (0.5%) and high (2%) concentrations displayed an opposite DNA methylation pattern. These six genes' promoter were all hypomethylated by 0.5% sevoflurane whereas hypermethylated by 2% sevoflurane, accompanied with the opposite transcriptional activity. We further verified that the DNMT1 binding ability contributed to DNA methylation these six genes' promoter. Moreover, we also captured DNMT1 and identified REC8 meiotic recombination protein (REC8) as the specific binding protein only existed in ATII cells treated with 0.5% sevoflurane rather than 2% and control. The binding ability of REC8 on these target genes' promoter showed highly positive correlation with DNMT1. In summary, we uncovered a potential epigenetic role of sevoflurane with low concentration in ATII cells of COPD that may help us deeply understand the pathogenesis and treatment mechanism of inhaled anesthesia drugs in COPD via a dose-dependent manner.

Sequential inspiratory muscle exercise-noninvasive positive pressure ventilation alleviates oxidative stress in COPD by mediating SOCS5/JAK2/STAT3 pathway

BACKGROUND

Pulmonary rehabilitation training is of great significance for the prognosis of chronic obstructive pulmonary disease (COPD) patients. The purpose of this study was to investigate the therapeutic effect and pathway of a new sequential noninvasive positive pressure ventilation (NIPPV) + inspiratory muscle training (IMT) therapy.

METHODS

A total of 100 COPD patients were enrolled and randomly divided into oxygen therapy (OT), NIPPV, IMT and sequential (NIPPV + IMT) group. Lung function, exercise endurance, quality of life, and dyspnea symptoms were examined and recorded. Then, reactive oxygen species (ROS), malonaldehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) levels were detected by enzyme-linked immunoassay, and suppressor of cytokine signaling 5 (SOCS5)/janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway expression changes were detected by quantitative real time-polymerase chain reaction (qRT-PCR) and western blot. A mouse model of COPD was then established to further verify the effects of SOCS5/JAK2/STAT3 pathways on lung function and oxidative stress.

RESULTS

After 8 weeks of treatment, NIPPV, IMT or sequential (NIPPV + IMT) significantly improved exercise endurance, quality of life and dyspnea, reduced oxidative stress, promoted SOCS5 expression and inhibited the activation of JAK2/STAT3 pathway, and no significant effect was observed on lung function of COPD patients. Notably, sequential (NIPPV + IMT) showed better therapeutic outcomes than either IMT or NIPPV alone. Moreover, results at the animal level showed that overexpression of SOCS5 significantly reduced pulmonary inflammatory infiltration, pathological changes and oxidative stress levels in COPD mice, enhanced lung function, and inhibited the activation of JAK2/STAT3 pathway.

CONCLUSION

Our results elucidated that sequential (NIPPV + IMT) significantly relieved COPD development by regulating SOCS5/JAK2/STAT3 signaling-mediated oxidative stress.

Significant role of circRNA BBS9 in chronic obstructive pulmonary disease via miRNA-103a-3p/BCL2L13

BACKGROUND

Various studies have shown that circular RNA (circRNA) plays a pivotal role in chronic obstructive pulmonary disease (COPD). We aimed to determine the role of circRNA BBS9 in COPD progression.

METHODS

Real-time quantitative reverse transcription PCR (qRT-PCR) was performed to determine the levels and the linkages of circRNA BBS9, miRNA-103a-3p, and BCL2L13 in cigarette smoke extract (CSE)-treated human pulmonary microvascular endothelial cells (HPMECs). The target binding sites of circRNA BBS9 and miRNA-103a-3p were predicted using the starBase database, and the TargetScan algorithm was used to forecast the potential binding sites of BCL2L13 and miRNA-103a-3p, which were verified using a dual-luciferase reporter assay. An flow cytometry (FCM) assay was performed to determine the rate of apoptosis of HPMECs. Caspase3 activity was determined using a Caspase3 assay kit. The apoptosis-related protein bands were determined by western blotting.

RESULTS

The level of circRNA BBS9 increased in 1% CSE-induced cells, and silencing of circRNA BBS9 decreased the ratio of apoptotic cells among the 1% CSE-induced HPMECs. The results of dual-luciferase reporter assays showed that miRNA-103a-3p associates with circRNA BBS9. miRNA-103a-3p was downregulated in COPD, and upregulation of miRNA-103a-3p inhibited apoptosis in CSE-stimulated cells. Moreover, BCL2L13 was found to act downstream of miRNA-103a-3p. Silencing of miRNA-103a-3p reversed the inhibitory effect of circRNA BBS9-siRNA. The effects of the miRNA-103a-3p mimic were reversed by the BCL2L13-plasmid.

CONCLUSION

circRNA BBS9 is involved in COPD development as it inhibits the functioning of miRNA-103a-3p. Our results suggest that circRNA BBS9 may act as a novel target for treating COPD.

Lung cancer patients with chronic obstructive pulmonary disease benefit from anti-PD-1/PD-L1 therapy

Lung cancer (LC) and chronic obstructive pulmonary disease (COPD) are two of the most fatal respiratory diseases, seriously threatening human health and imposing a heavy burden on families and society. Although COPD is a significant independent risk factor for LC, it is still unclear how COPD affects the prognosis of LC patients, especially when LC patients with COPD receive immunotherapy. With the development of immune checkpoint inhibition (ICI) therapy, an increasing number of inhibitors of programmed cell death-1 (PD-1) and PD-1 ligand (PD-L1) have been applied to the treatment of LC. Recent studies suggest that LC patients with COPD may benefit more from immunotherapy. In this review, we systematically summarized the outcomes of LC patients with COPD after anti-PD-1/PD-L1 treatment and discussed the tumor immune microenvironment (TIME) regulated by COPD in LC immunotherapy, which provides novel insights for the clinical treatment of LC patients with COPD.