Daily Respiratory Research Analysis
Analyzed 69 papers and selected 3 impactful papers.
Summary
Three high-impact studies span mechanistic pulmonary vascular biology, pandemic preparedness, and acute respiratory support. A Nature portfolio study identifies an endothelial USP2a–METTL16 positive feedback loop driving IL-6–linked pulmonary hypertension and shows genetic/pharmacological inhibition alleviates disease in preclinical models. Complementing this, a Nature Communications tool (RAISE) predicts sarbecovirus human spillover potential, while a Lancet Respiratory Medicine network meta-analysis finds CPAP, HFNC, and bilevel NIPPV reduce intubation in acute hypoxaemic respiratory failure, with CPAP/HFNC likely lowering mortality.
Research Themes
- Endothelial signaling and pulmonary hypertension therapeutics
- Computational risk stratification for zoonotic coronaviruses
- Optimizing non-invasive respiratory support in acute hypoxaemic respiratory failure
Selected Articles
1. Endothelial USP2a-METTL16 loop potentiates IL-6 signaling via m
The study identifies a self-reinforcing endothelial USP2a–METTL16 loop that amplifies IL-6-driven pulmonary vascular remodeling. Endothelial-specific Usp2a deletion or pharmacologic USP2a inhibition (ML364) mitigated experimental pulmonary hypertension, establishing this axis as a therapeutic target.
Impact: Revealing a druggable, self-reinforcing USP2a–METTL16 loop provides a mechanistic basis and actionable target for pulmonary hypertension, a disease with limited disease-modifying options. It links IL-6 signaling to endothelial remodeling via ubiquitin and RNA-binding pathways.
Clinical Implications: Targeting USP2a pharmacologically (e.g., ML364-like inhibitors) or disrupting USP2a–METTL16 stabilization could emerge as a novel disease-modifying strategy in pulmonary hypertension alongside current vasodilators.
Key Findings
- USP2a is upregulated in lung tissues from PH patients, preclinical PH models, and IL-6–stimulated endothelial cells.
- Endothelial-specific Usp2a deletion and pharmacologic inhibition with ML364 alleviate experimental PH manifestations.
- USP2a deubiquitinates METTL16, preventing its degradation; METTL16 in turn increases USP2a expression via eIF3a/eIF3b interactions, forming a self-reinforcing loop.
Methodological Strengths
- Use of human PH tissues, multiple preclinical PH models, and IL-6–stimulated endothelial cells to establish relevance across systems.
- Genetic (endothelial-specific knockout) and pharmacological (ML364) interventions providing convergent causal evidence.
- Molecular mechanistic dissection of protein stability and translational regulation (USP2a–METTL16–eIF3a/eIF3b interactions).
Limitations
- The abstracted results are preclinical; no human interventional data are presented.
- Downstream m6A-related mechanisms are truncated in the abstract, limiting detailed insight into terminal effectors.
- Safety, specificity, and pharmacokinetics of USP2a inhibition in vivo require further evaluation.
Future Directions: Define the full downstream transcriptomic/m6A program in PH endothelium, optimize selective USP2a inhibitors, and evaluate efficacy/safety in large-animal PH models and early-phase human trials.
Dysfunction of vascular endothelial cells is recognized as a critical driver in pulmonary vascular remodeling of pulmonary hypertension (PH). Although interleukin-6 (IL-6) has been firmly established as an indispensable factor leading to pulmonary vascular remodeling, its downstream molecular mechanisms remain incompletely elucidated. Here, we discover that ubiquitin-specific protease 2a (USP2a) is upregulated in lung tissues of PH patients and preclinical PH models, and in IL-6-stimulated endothelial cells. Both the endothelial cell-specific Usp2a genetic deletion and the pharmacological inhibition of USP2a with the inhibitor ML364 alleviate experimental PH manifestations. Mechanistically, USP2a attenuates the degradation of methyltransferase-like 16 (METTL16) by deubiquitination. Notably, METTL16 reciprocally enhances USP2a expression via interactions with eIF3a and eIF3b in a methyltransferase activity-independent manner, establishing a self-reinforcing USP2a-METTL16 regulatory loop. Subsequent investigations reveal that METTL16 enhances N6-methyladenosine (m
2. RAISE: A computational tool for evaluating sarbecovirus spillover potential.
RAISE integrates structure-based prediction and interaction scoring to classify sarbecoviruses by human ACE2-binding potential and identifies mutations (e.g., T498Y/W) that enable spillover. Prospective application to merbecoviruses indicates generalizability and provides a prioritization roadmap for surveillance.
Impact: Provides an actionable, generalizable framework to anticipate zoonotic risk before emergence, directly informing surveillance and pandemic preparedness for respiratory coronaviruses.
Clinical Implications: While not immediately altering bedside care, RAISE can steer public health surveillance, strain prioritization for countermeasure development, and risk communication, indirectly protecting clinical systems from surge threats.
Key Findings
- Developed RAISE, a computational framework integrating structural predictions with interaction scoring to estimate hACE2 binding.
- Classified sarbecoviruses into high, negligible, and 'poised' spillover potential groups based on predicted RBD–hACE2 interactions.
- Identified mutations (e.g., T498Y/W) that enabled hACE2 utilization in poised viruses (PDF-2370, Khosta-1) and broadened cross-species ACE2 binding.
- Demonstrated generalizability by prospectively applying the model to merbecoviruses.
Methodological Strengths
- Integration of structure-based modeling with interaction scoring for mechanistically grounded predictions.
- Mutation screening providing functional validation of predicted ACE2 utilization shifts.
- Prospective application across coronavirus lineages to assess generalizability.
Limitations
- Primarily computational; broad experimental validation across diverse sarbecoviruses and in vivo fitness/virulence not presented.
- Spillover risk entails ecological and host factors beyond receptor binding not captured by the model.
Future Directions: Couple RAISE outputs with experimental pseudovirus panels and animal models, and integrate ecological/host range data to refine composite spillover scores for operational surveillance.
Animal sarbecoviruses, relatives of SARS-CoV or SARS-CoV-2, pose a significant zoonotic threat driven by their ability to bind the human ACE2 (hACE2) receptor. To address challenges in evaluating these threats, we developed RAISE (Receptor binding domain-hACE2 Interaction Scoring Evaluation), a computational framework that integrates structural predictions with interaction scoring. By scoring predicted hACE2 interactions, our RAISE model categorized sarbecoviruses into three groups: high potential (hACE2-binding), negligible potential (hACE2-nonbinding), and an intermediate "poised" state (a state defined by either weak binding activity or a high potential to evolve it). Mutation screening of two "hACE2-poised" sarbecoviruses, PDF-2370 and Khosta-1 using RAISE, revealed mutations such as T498Y/W that enabled human ACE2 utilization and expanded their ability to bind to ACE2 receptors from a broader range of species. The model's generalizability was further demonstrated through prospective application to merbecoviruses, highlighting its utility in preemptively assessing zoonotic threats across coronavirus lineages. RAISE provides a predictive roadmap for prioritizing risk viruses and guiding pandemic preparedness.
3. Non-invasive respiratory supports and criteria for intubation in randomised trials of acute hypoxaemic respiratory failure: a systematic review and network meta-analysis.
Across 44 RCTs (n=9704), CPAP (OR 0.45), HFNC (OR 0.61), and bilevel NIPPV (OR 0.60) probably reduce intubation versus standard oxygen. CPAP (OR 0.73) and HFNC (OR 0.83) may reduce mortality; explicit intubation criteria did not modify treatment effects.
Impact: Provides high-certainty comparative evidence to support non-invasive strategies in AHRF and clarifies that trial intubation criteria do not bias observed benefits.
Clinical Implications: For adults with AHRF, consider CPAP or HFNC to reduce intubation risk, with potential mortality benefit; bilevel NIPPV also reduces intubation. Institutions without explicit intubation criteria can reasonably apply these findings.
Key Findings
- In 44 RCTs including 9704 patients, CPAP, HFNC, and bilevel NIPPV reduced intubation versus standard oxygen therapy.
- CPAP and HFNC may reduce mortality compared with standard oxygen; the certainty is lower for mortality than for intubation.
- Presence of predefined intubation criteria in trials was not associated with differences in estimated treatment effects.
Methodological Strengths
- Pre-registered protocol with comprehensive multi-database search, RoB 2 bias assessment, and GRADE certainty ratings.
- Network meta-analysis enabling indirect comparisons across CPAP, HFNC, and bilevel NIPPV with meta-regression on intubation criteria.
Limitations
- Mortality effects were of low certainty and may be influenced by between-trial heterogeneity and co-interventions.
- Variation in device settings, escalation protocols, and patient selection across trials may limit applicability to specific contexts.
Future Directions: Head-to-head pragmatic RCTs of CPAP vs HFNC with standardized protocols and patient-centered outcomes (comfort, failure-to-intubate harms), and implementation research in varied resource settings.
BACKGROUND: Patients with acute hypoxaemic respiratory failure (AHRF) can be treated with non-invasive respiratory supports. We aimed to update a network meta-analysis of these treatments, and investigate whether the use of criteria for intubation in trials influences treatment effects on intubation or mortality. METHODS: For this systematic review and meta-analysis, we updated a literature search that was done in 2022 for the previous network meta-analysis examining non-invasive oxygen supports for AHRF. We searched MEDLINE, Embase, Cochrane CENTRAL, CINAHL, Web of Science, and PubMed databases from database inception to Nov 18, 2025, for randomised controlled trials studying adults (18 years or older) with AHRF, comparing non-invasive respiratory supports or comparing the use of non-invasive respiratory support to standard oxygen therapy (SOT). We excluded trials enrolling patients already receiving invasive ventilation, trials that included invasive ventilation as an intervention, trials where the majority (>50%) of patients had congestive heart failure or chronic obstructive pulmonary disease as their primary reason for respiratory failure, and trials focusing on patients who were immediately postextubation or postoperative. Data were extracted from published reports. We catalogued intubation criteria and performed a network meta-analysis comparing the effects of continuous positive airway pressure (CPAP), high-flow nasal cannula (HFNC), and bilevel non-invasive positive pressure ventilation (NIPPV) on intubation and mortality, presented as odds ratios (ORs) and 95% credible intervals (CrIs) relative to SOT. We assessed risk of bias with the RoB 2 tool and certainty with the GRADE approach. We used network meta-regression to assess whether trials with intubation criteria found different treatment effects. The protocol was pre-registered on Jan 23, 2024, with Open Science Framework, https://osf.io/f8qeh. FINDINGS: We included 44 trials (33 from previous review, 11 newly identified) that enrolled 9704 patients. The median proportion of participants who were female was 37% (IQR 29-45) and the median proportion male was 63% (55-71). The network for intubation included 8790 patients and 42 comparisons from 37 trials. The network for mortality included 8789 patients and 39 comparisons from 34 trials. Intubation criteria were present in 37 (84%) trials, and most pertained to oxygenation, ventilation, or neurological state. Compared with SOT, CPAP (OR 0·45, 95% CrI 0·27-0·72), HFNC (OR 0·61, 0·42-0·86), and bilevel NIPPV (OR 0·60, 0·39-0·89) probably reduce intubation (all moderate certainty). CPAP (OR 0·73, 0·55-0·95) and HFNC (OR 0·83, 0·66-0·98) may reduce mortality compared with SOT (both low certainty), whereas bilevel NIPPV (OR 0·93, 0·71-1·17; low certainty) may not. Criteria for intubation were not associated with differences in treatment effects. INTERPRETATION: Compared with SOT, CPAP, HFNC, and bilevel NIPPV probably reduce intubation, and CPAP and HFNC may reduce mortality. Criteria for intubation were common but were not associated with differences in treatment efficacy. These findings can guide the selection of non-invasive respiratory supports for patients, inform policymakers regarding the utility of non-invasive respiratory supports, and provide reassurance that results from trials incorporating intubation criteria likely extend to contexts where explicit intubation criteria are not used. FUNDING: JP Bickell Foundation.