Single-Cell Sequencing of Lung Macrophages and Monocytes Reveals Novel Therapeutic Targets in COPD

What Single Cell RNA Sequencing Has Taught Us about Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) affects close to 400 million people worldwide and is the 3rd leading cause of mortality. It is a heterogeneous disorder with multiple endophenotypes, each driven by specific molecular networks and processes. Therapeutic discovery in COPD has lagged behind other disease areas owing to a lack of understanding of its pathobiology and scarcity of biomarkers to guide therapies. Single cell RNA sequencing (scRNA-seq) is a powerful new tool to identify important cellular and molecular networks that play a crucial role in disease pathogenesis. This paper provides an overview of the scRNA-seq technology and its application in COPD and the lessons learned to date from scRNA-seq experiments in COPD.

Dissecting causal relationships between immune cells, plasma metabolites, and COPD: a mediating Mendelian randomization study

Objective

This study employed Mendelian Randomization (MR) to investigate the causal relationships among immune cells, COPD, and potential metabolic mediators.

Methods

Utilizing summary data from genome-wide association studies, we analyzed 731 immune cell phenotypes, 1,400 plasma metabolites, and COPD. Bidirectional MR analysis was conducted to explore the causal links between immune cells and COPD, complemented by two-step mediation analysis and multivariable MR to identify potential mediating metabolites.

Results

Causal relationships were identified between 41 immune cell phenotypes and COPD, with 6 exhibiting reverse causality. Additionally, 21 metabolites were causally related to COPD. Through two-step MR and multivariable MR analyses, 8 cell phenotypes were found to have causal relationships with COPD mediated by 8 plasma metabolites (including one unidentified), with 1-methylnicotinamide levels showing the highest mediation proportion at 26.4%.

Conclusion

We have identified causal relationships between 8 immune cell phenotypes and COPD, mediated by 8 metabolites. These findings contribute to the screening of individuals at high risk for COPD and offer insights into early prevention and the precocious diagnosis of Pre-COPD.

Single-Cell Profiling Reveals Immune-Based Mechanisms Underlying Tumor Radiosensitization by a Novel Mn Porphyrin Clinical Candidate, MnTnBuOE-2-PyP5+ (BMX-001)

Manganese porphyrins reportedly exhibit synergic effects when combined with irradiation. However, an in-depth understanding of intratumoral heterogeneity and immune pathways, as affected by Mn porphyrins, remains limited. Here, we explored the mechanisms underlying immunomodulation of a clinical candidate, MnTnBuOE-2-PyP5+ (BMX-001, MnBuOE), using single-cell analysis in a murine carcinoma model. Mice bearing 4T1 tumors were divided into four groups: control, MnBuOE, radiotherapy (RT), and combined MnBuOE and radiotherapy (MnBuOE/RT). In epithelial cells, the epithelial-mesenchymal transition, TNF-α signaling via NF-кB, angiogenesis, and hypoxia-related genes were significantly downregulated in the MnBuOE/RT group compared with the RT group. All subtypes of cancer-associated fibroblasts (CAFs) were clearly reduced in MnBuOE and MnBuOE/RT. Inhibitory receptor-ligand interactions, in which epithelial cells and CAFs interacted with CD8+ T cells, were significantly lower in the MnBuOE/RT group than in the RT group. Trajectory analysis showed that dendritic cells maturation-associated markers were increased in MnBuOE/RT. M1 macrophages were significantly increased in the MnBuOE/RT group compared with the RT group, whereas myeloid-derived suppressor cells were decreased. CellChat analysis showed that the number of cell-cell communications was the lowest in the MnBuOE/RT group. Our study is the first to provide evidence for the combined radiotherapy with a novel Mn porphyrin clinical candidate, BMX-001, from the perspective of each cell type within the tumor microenvironment.

Assessing causality between chronic obstructive pulmonary disease with depression: A bidirectional Mendelian randomization study

PURPOSE

Our investigation utilized a two-sample Mendelian randomization approach to explore the ambiguous bidirectional relationship between Chronic Obstructive Pulmonary Disease (COPD) and depression, furthering insights from existing observational studies.

METHODS

In this study, we conducted a bidirectional Mendelian randomization using genome-wide association studies (GWAS) datasets. We initially analyzed depression data from the Psychiatric Genomics Consortium and the UK Biobank (n = 500,199), alongside COPD data from the FinnGen Consortium (n = 329,552). The second phase involved comparing depression data from FinnGen (n = 372,472) with COPD data from the UK Biobank (n = 361,194). Our Mendelian analysis employs various methods to guarantee a comprehensive and rigorous investigation.

RESULTS

In the initial analytic phase utilizing the inverse variance weighted (IVW) method, COPD does not significantly contribute to the incidence of depression (IVW odds ratio (OR) = 0.989, 95 % confidence interval (CI) = 0.895 to 1.092, P = 0.824). Conversely, the data suggested a statistically significant association where depression may precipitate the development of COPD, with a notable increase in risk (IVW OR = 1.421, 95 % CI = 1.149 to 1.756, P = 0.001). Subsequent validation through a second-step analysis reinforced the hypothesis that depression elevates the likelihood of COPD onset (IVW OR = 1.002, 95 % CI = 1.0003 to 1.0046, P = 0.028).

CONCLUSION

Our study, utilizing Mendelian randomization analysis, determined that COPD does not escalate the risk of depression. Conversely, our analysis suggests that depression may elevate the risk of developing COPD. This insight underscores the importance of enhancing prevention, screening, and treatment strategies for COPD in individuals with depression.