Daily Respiratory Research Analysis
Analyzed 81 papers and selected 3 impactful papers.
Summary
Three high-impact studies advance respiratory science across pathophysiology and translational therapy. A Nature Genetics single-nucleus atlas dissects COPD heterogeneity, revealing spatially organized pathological niches and blood biomarkers. Complementing this, a Molecular Therapy study introduces a myeloid CAR platform that mitigates lung fibrosis in vivo, while a Communications Biology paper identifies an epigenetic KDM7A–TLR8 axis that restrains profibrotic macrophage states.
Research Themes
- Single-cell and spatial multi-omics mapping of COPD heterogeneity
- Allogeneic CAR-macrophage strategies for fibrotic lung disease
- Epigenetic control of profibrotic macrophage polarization (KDM7A–TLR8)
Selected Articles
1. Aberrant cellular communities underlying disease heterogeneity in chronic obstructive pulmonary disease.
Using single-nucleus RNA-seq, spatial transcriptomics, and proteomics, this study maps COPD cellular heterogeneity across 141 lungs. It identifies early epithelial regenerative states that wane with progression and expanding profibrotic/remodeling states and immune subsets, defines spatially localized niches, and nominates plasma biomarkers and intercellular networks linked to disease severity.
Impact: This atlas provides a high-resolution reference linking cell states to clinical measures, enabling biomarker development and targeted therapeutic hypotheses for COPD.
Clinical Implications: Facilitates patient stratification using plasma biomarkers of pathological cell states and supports designing trials targeting profibrotic/remodeling niches or their signaling networks.
Key Findings
- Single-nucleus RNA-seq of 1,516,727 nuclei revealed COPD stage-linked shifts in cell composition and emergent states.
- Early epithelial regenerative states declined with progression, while profibrotic/remodeling states and select immune populations expanded.
- Spatial transcriptomics defined localized co-occurring pathological niches; plasma proteomics identified biomarkers tied to extracellular matrix remodeling.
- Mediation and cell–cell communication analyses uncovered networks associated with disease severity.
Methodological Strengths
- Large-scale multi-omics integration (single-nucleus RNA-seq, spatial transcriptomics, proteomics).
- Direct linkage of cellular states to clinical phenotypes with rigorous computational analyses.
Limitations
- Cross-sectional design limits causal inference and temporal dynamics.
- External prospective validation and functional perturbation studies are needed to confirm therapeutic targets.
Future Directions: Develop and validate blood-based biomarker panels for stratification; test interventions that modulate profibrotic/remodeling cell states and intercellular networks; longitudinal single-cell studies to track trajectories.
Chronic obstructive pulmonary disease (COPD) is clinically and molecularly heterogeneous. To investigate COPD heterogeneity, we profiled lung tissue by single-nucleus RNA sequencing from 141 study participants (1,516,727 nuclei) and identified shifts in cell composition and emergent cell states that correlated with lung function, emphysema and composite symptom scores. Epithelial regenerative states peaked in early COPD and declined thereafter, whereas inflamed nonimmune cells and profibrotic/remodeling states, together with select immune populations, expanded with disease progression. Clustering study participants by the proportion of pathologic cells coupled with spatial transcriptomics identified distinct patterns of cellular co-occurrence within spatially localized niches. Proteomic analyses identified plasma biomarkers of cell states and their impact on the extracellular matrix. Mediation and cell communication analyses revealed cell-autonomous and intercellular communication networks associated with disease. These data define the cellular landscape of COPD heterogeneity, revealing molecular drivers and biomarkers that could inform therapeutic strategies.
2. Myeloid lineage CAR knock-in mice enable allogeneic immunotherapy for liver and lung fibrosis.
This work introduces an in vivo source of CAR macrophages: myeloid-specific FAP-CAR knock-in mice resist induced fibrosis, and transferring their macrophages or whole blood mitigates pulmonary and hepatic fibrosis in recipients. It overcomes key manufacturing bottlenecks and supports allogeneic cell therapy concepts for fibrotic diseases.
Impact: Proposes a paradigm-shifting route to source therapeutic CAR-Ms directly from living donors, reducing complexity and enabling scalable, potentially off-the-shelf anti-fibrotic immunotherapy.
Clinical Implications: Suggests future allogeneic CAR-M–based interventions for pulmonary fibrosis, pending safety, immunogenicity, and efficacy testing in humanized/large-animal models and early-phase trials.
Key Findings
- FAP-targeted CAR macrophages reduced fibrosis in both pulmonary and hepatic mouse models.
- Myeloid-specific FAP-CAR knock-in mice exhibited inherent resistance to induced fibrosis.
- Transplantation of CAR-Ms or allogeneic whole blood from transgenic donors alleviated fibrosis in recipient mice.
Methodological Strengths
- Convergent validation across in vitro assays and multiple in vivo fibrosis models.
- Genetic lineage-specific CAR expression and functional transplantation experiments.
Limitations
- Findings are preclinical and in mice; human translation and immunogenicity remain uncertain.
- Safety and off-target effects of allogeneic blood transfer and CAR-M require comprehensive evaluation.
Future Directions: Engineer human CAR-M platforms, develop allogeneic compatibility strategies, perform large-animal studies, and initiate phase 1 trials in pulmonary fibrosis.
The preparation of chimeric antigen receptor immune cells (CAR-IC) typically involves a costly and time-intensive process. Moreover, the transduction of CAR genes into immune cells, particularly macrophages, presents inherent challenges. Here we report a novel strategy to obtain CAR-modified macrophages (CAR-Ms) directly from living animals to treat pulmonary and hepatic fibrosis. We first validated adenovirus-transduced CAR-Ms targeting fibroblast activation protein (FAP) in vitro, as well as in mouse models of pulmonary and hepatic fibrosis. Using a Cre/LoxP strategy, we generated mice with myeloid-specific expression of FAP-CAR, which showed inherent resistance to induced fibrosis. Furthermore, transplantation of macrophages or allogeneic transfusion of whole blood from these transgenic mice alleviated fibrosis in recipient mice. This proof-of-concept study sourcing gene-modified immune cells directly from living animals shows promise as a therapeutic platform to treat various diseases.
3. Histone demethylase KDM7A negatively regulates fibrotic macrophage polarization and lung fibrosis progression.
The study identifies KDM7A as an epigenetic brake on profibrotic macrophage polarization. Kdm7a loss exacerbates bleomycin-induced lung fibrosis and expands Fib-Mac states, partly by reducing TLR8 expression via H3K27me2 at its enhancer. Human fibrosis tissue supports relevance, nominating the KDM7A–TLR8 axis as a therapeutic target.
Impact: Reveals a druggable epigenetic–innate immune axis controlling profibrotic macrophage states, offering mechanistic rationale for antifibrotic therapies targeting macrophage polarization.
Clinical Implications: Supports development of small-molecule modulators of KDM7A or TLR8 agonism to restrain profibrotic macrophage states in lung fibrosis, with potential age/sex stratification.
Key Findings
- Kdm7a knockout reprogrammed macrophages toward profibrotic (Fib-Mac) states and worsened bleomycin-induced lung fibrosis.
- KDM7A maintained TLR8 expression by modulating H3K27me2 at an enhancer; TLR8 suppressed profibrotic polarization.
- Macrophage Kdm7a and Tlr8 expression declined with age in male mice; human fibrosis tissue corroborated relevance.
Methodological Strengths
- Integration of single-cell RNA-seq, genetic knockout models, and validation in human fibrosis tissue.
- Mechanistic link from epigenetic mark (H3K27me2) to innate receptor expression (TLR8).
Limitations
- Relies on murine bleomycin models which only partially recapitulate human fibrosis.
- No in vivo pharmacologic modulation of KDM7A/TLR8 demonstrated.
Future Directions: Develop selective KDM7A modulators or TLR8 agonists; test across fibrosis models and assess biomarkers for patient stratification and age/sex effects.
Macrophage polarization shapes immune responses in inflammation and fibrosis, yet the epigenetic mechanisms restraining pathogenic states remain unclear. Here, we identify lysine-specific demethylase 7 A (KDM7A) as an epigenetic suppressor of a profibrotic macrophage (Fib-Mac). Using macrophage assays, single-cell RNA sequencing of Kdm7a-knockout mice, and lung tissue from fibrosis patients, we show that Kdm7a loss drives transcriptional and metabolic reprogramming toward Fib-Mac states. Kdm7a-knockout mice exhibit exacerbated bleomycin-induced lung fibrosis with the expansion of Fib-Mac populations. Mechanistically, we identify toll-like receptor 8 (TLR8) as a suppressor of Fib-Mac polarization whose expression is regulated by KDM7A via the repressive mark H3K27me2 at its enhancer. Notably, macrophage Kdm7a and Tlr8 expression declines with age in male mice, consistent with clinical risk patterns. These findings uncover an epigenetic mechanism restraining disease-driving macrophage states and suggest the KDM7A-TLR8 axis as a potential therapeutic target in fibrotic disorders.