Daily Respiratory Research Analysis
Analyzed 74 papers and selected 3 impactful papers.
Summary
Analyzed 74 papers and selected 3 impactful articles.
Selected Articles
1. E-cigarette aerosols induce the hydrolysis of lysosomal glycerophospholipids through PLA2G4A activation initiated by nicotine binding to CHRNA3/α3 nAchr in airway epithelial cells.
Nicotine in e-cigarette aerosols activates CHRNA3 (α3 nAChR) to raise intracellular Ca2+, engages PLA2G4A, hydrolyzes lysosomal glycerophospholipids, and permeabilizes lysosomal membranes, thereby blocking autolysosomal degradation despite inducing autophagosome formation. Restoring lysosomal membrane integrity rescues autophagy and mitigates airway epithelial injury.
Impact: This study delineates a receptor-to-enzyme pathway linking nicotine exposure to lysosomal injury and autophagy blockade in airway epithelium, identifying CHRNA3 and PLA2G4A as actionable nodes.
Clinical Implications: Findings support stricter regulation of vaping and suggest therapeutic strategies that stabilize lysosomes or inhibit PLA2G4A to protect airway epithelium in users with e-cigarette–associated injury.
Key Findings
- Nicotine triggered autophagosome formation via MTOR inhibition but concomitantly blocked autolysosomal degradation through lysosomal membrane permeabilization.
- Restoration of lysosomal membrane integrity reversed LMP, rescued autophagy, and alleviated airway epithelial damage.
- Mechanistically, nicotine binding to CHRNA3/α3 nAChR elevated Ca2+ to activate PLA2G4A, hydrolyzing the sn-2 bond of lysosomal glycerophospholipids to produce lysophospholipids and permeabilize lysosomes.
Methodological Strengths
- Multi-system validation in mouse airway epithelium and human bronchial epithelial cells with mechanistic rescue experiments
- Causal linkage from receptor activation (CHRNA3) to enzymatic effector (PLA2G4A) and organelle-level pathology (LMP)
Limitations
- Preclinical models without human clinical outcome data
- Exposure scope focused on nicotine; contributions of other aerosol constituents were not fully delineated
Future Directions: Test pharmacologic PLA2G4A inhibitors and lysosomal stabilizers in vivo; evaluate CHRNA3 genetic variants as susceptibility modifiers; develop airway biomarkers of LMP for exposure-risk stratification.
Accumulating evidence has demonstrated a significant association between e-cigarette exposure and airway epithelial damage. Nevertheless, the molecular drivers orchestrating this pathology remain unclear. Here, we demonstrated that nicotine is the key component of e-cigarette aerosols that induced pathogenic changes, including apoptosis, oxidative stress, and mucus overproduction, in mouse airway epithelium and in human bronchial epithelial (HBE) cells. We further established that the nicotine of e-cigarette aerosols induced autophagosome formation via MTOR inhibition, while concurrently suppressing autolysosomal degradation through lysosomal membrane permeabilization (LMP). Restoration of lysosomal membrane integrity reversed e-cigarette aerosol-induced LMP and the subsequent macroautophagy/autophagy inhibition, thereby alleviating airway epithelial damage. Mechanistically, nicotine of e-cigarette aerosols permeabilized lysosomal membranes via calcium-dependent activation of PLA2G4A, which hydrolyzed the sn-2 ester bond of lysosomal glycerophospholipids, generating lysophospholipids. This process was initiated by nicotine binding to CHRNA3/α3 nAChR, a ligand-gated ion channel whose activation triggered intracellular Ca
2. ZFP91 restricts RSV replication by driving K48-linked ubiquitination and proteasomal degradation of M2-1.
The E3 ligase ZFP91 is upregulated by RSV infection and limits replication by directly binding M2-1 and catalyzing K48-linked polyubiquitination at K8, K48, and K52, driving proteasomal degradation. Airway epithelial loss of ZFP91 in mice increases lung viral burden and M2-1, validating ZFP91 as a host antiviral regulator in vivo.
Impact: Identifying a druggable host E3 ligase that targets a critical RSV cofactor (M2-1) adds a new antiviral paradigm beyond direct-acting agents and suggests host-directed therapies resilient to viral escape.
Clinical Implications: Therapeutically boosting ZFP91 activity or mimicking its M2-1 ubiquitination could complement existing RSV preventives/therapeutics, potentially reducing resistance risk due to host-targeting.
Key Findings
- RSV infection upregulated ZFP91; overexpression suppressed RSV replication while knockdown increased viral titers and gene expression.
- Airway epithelial-specific ZFP91 loss in mice increased lung viral burden and M2-1 protein levels, confirming in vivo antiviral function.
- ZFP91 directly bound M2-1 and catalyzed K48-linked polyubiquitination at K8, K48, and K52, promoting proteasomal degradation.
Methodological Strengths
- In vivo validation using epithelial-specific loss-of-function model confirming antiviral role
- Molecular mapping of ubiquitination sites and direct protein–protein interaction evidence
Limitations
- Lack of translational data in primary human airway tissues or clinical samples
- No small-molecule modulators of ZFP91 tested to demonstrate therapeutic feasibility
Future Directions: Develop small-molecule activators or PROTAC-like approaches to enhance M2-1 degradation; validate ZFP91 pathway in primary human airway cells and RSV clinical isolates.
Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in children. Among viral components, the M2-1 protein is essential for efficient transcription and replication. Given its pivotal role in the viral life cycle, host factors that regulate this process may represent potential therapeutic targets against RSV. In this study, we identified the E3 ubiquitin ligase ZFP91 as a host factor that restricts RSV replication. Notably, RSV infection upregulated ZFP91 expression; ZFP91 overexpression significantly suppressed viral replication, whereas ZFP91 knockdown increased viral titers and viral gene expression, including that of M2-1 and N. Importantly, in an RSV-infected mouse model, epithelial-specific loss of ZFP91 increased viral burden and M2-1 protein levels in lung tissues, confirming its antiviral function in vivo. Mechanistically, ZFP91 directly interacted with M2-1 and promoted its degradation by catalyzing K48-linked polyubiquitination at lysine residues 8, 48, and 52. Collectively, these findings identify ZFP91 as a key regulator of RSV replication and reveal a novel antiviral mechanism mediated by its E3 ubiquitin ligase activity. This work thus provides new insights into RSV pathogenesis and host-virus interactions.
3. Cadonilimab plus chemotherapy as first-line treatment in PD-L1-negative advanced non-small cell lung cancer: a phase II clinical trial.
Cadonilimab (PD-1/CTLA-4 bispecific) plus chemotherapy achieved a 12-month PFS rate of 42.1%, ORR 66%, and DCR 100% in PD-L1-negative advanced NSCLC, with manageable grade ≥3 TRAEs in 52%. cfDNA methylation-based molecular response predicted clinical response about five cycles earlier, and baseline methylation risk stratified PFS.
Impact: Demonstrates promising efficacy in a hard-to-treat PD-L1-negative population and integrates a cfDNA methylation-based metric that anticipates response earlier than imaging, advancing precision monitoring.
Clinical Implications: Supports further randomized evaluation of cadonilimab plus chemotherapy as a first-line option in PD-L1-negative NSCLC and suggests implementing cfDNA methylation monitoring to guide earlier treatment decisions.
Key Findings
- Primary endpoint met: 12-month PFS rate 42.1% (95% CI 29.6–60.0).
- Secondary outcomes: median PFS 9.7 months; ORR 66.0%; DCR 100%; median duration of response 9.5 months; median OS not reached.
- Grade ≥3 treatment-related adverse events in 52% of patients; safety manageable.
- cfDNA methylation-based molecular response predicted clinical response about five cycles earlier than radiographic assessment and baseline methylation risk scores correlated with PFS (11.4 vs 6.9 months).
Methodological Strengths
- Prospective phase II design with prespecified efficacy threshold
- Embedded cfDNA methylation biomarker enabling early, quantitative response assessment
Limitations
- Single-arm, non-randomized phase II limits causal inference versus standard regimens
- Sample size and follow-up may be insufficient for mature OS and rare toxicities
Future Directions: Conduct randomized controlled trials versus standard chemoimmunotherapy and validate cfDNA methylation response as a surrogate endpoint and risk stratifier.
Although immunotherapy is approved for patients with high PD-L1 expression, optimal therapeutic strategies for PD-L1-negative populations remain undefined. This study (ChiCTR2300071681) assessed the efficacy and safety of cadonilimab (PD-1/CTLA-4 bispecific antibody) plus chemotherapy in patients with PD-L1-negative advanced non-small-cell lung cancer (NSCLC). The primary endpoint, 12-month progression-free survival (PFS) rate, is 42.1% (95% CI, 29.6%-60.0%), which has reached the prespecified threshold. Secondary endpoints include a median overall survival of not reached, a median PFS of 9.7 months, an objective response rate of 66.0%, a disease control rate of 100.0%, and a median duration of response of 9.5 months. Grade ≥3 treatment-related adverse events occur in 26 (52.0%) patients. cfDNA methylation-based molecular response predicts the actual clinical response approximately 5 cycles earlier than conventional radiographic evaluation. Baseline differentially methylated fragments scores show a significant correlation with PFS, with low-risk patients demonstrating a longer median PFS compared to high-risk patients (11.4 months versus 6.9 months). Overall, first-line cadonilimab plus chemotherapy shows an encouraging efficacy with a manageable safety profile for challenging-to-treat PD-L1-negative advanced NSCLC, warranting further evaluation in controlled studies.