Daily Respiratory Research Analysis
Analyzed 70 papers and selected 3 impactful papers.
Summary
Three impactful studies span mechanistic respiratory biology and population-level prevention. A Cell Reports study uncovers an epithelial lipid–ER stress–mitochondrial dysfunction axis driving asthma via CEPT1 deficiency. A Nature Communications paper shows ventrolateral medullary astrocytes modulate sighs and arousal under hypoxia. A Vaccine modeling analysis identifies optimal hybrid programs using maternal RSV vaccine and nirsevimab to reduce pediatric RSV hospitalizations cost-effectively.
Research Themes
- Airway epithelial lipid metabolism and ER stress as drivers of asthma
- Astroglial control of breathing–arousal coupling under hypoxia
- Hybrid RSV immunization strategies (maternal vaccine + nirsevimab) for infant protection
Selected Articles
1. FOXA1-mediated CEPT1 deficiency in airway epithelium drives asthma via an ER stress-mitochondrial dysfunction axis.
This study identifies CEPT1 downregulation in asthmatic airway epithelium as a driver of phospholipid imbalance, activating all three ER stress pathways, disrupting ER Ca2+ homeostasis, and promoting mitochondrial dysfunction. The work delineates a FOXA1–CEPT1 axis linking lipid metabolism to epithelial stress responses, offering therapeutic entry points to restore membrane phospholipids and attenuate inflammation.
Impact: It uncovers a mechanistic lipid–ER–mitochondria axis that explains epithelial dysfunction in asthma, revealing CEPT1 as a potential therapeutic target and biomarker.
Clinical Implications: Therapies that restore phosphatidylcholine balance or upregulate CEPT1, and interventions targeting ER stress/mitochondrial resilience, could reduce epithelial injury and airway hyperreactivity. CEPT1 expression may stratify patients for precision interventions.
Key Findings
- CEPT1, a key phospholipid biosynthetic enzyme, is significantly downregulated in asthmatic airway epithelium.
- CEPT1 deficiency reduces PC/PE, induces phospholipid imbalance, activates all three ER stress branches, and disrupts ER Ca2+ homeostasis.
- Mitochondrial dysfunction accompanies ER stress, linking epithelial metabolic defects to asthma pathophysiology.
- FOXA1 is implicated in regulating CEPT1, establishing a FOXA1–CEPT1 mechanistic axis.
Methodological Strengths
- Integrative discovery-to-validation pipeline combining data mining with in vitro and in vivo mechanistic assays
- Multi-axis readouts spanning lipidomics, ER stress signaling, Ca2+ homeostasis, and mitochondrial function
Limitations
- Preclinical mechanistic focus; causal validation in human tissues and clinical cohorts is pending
- Therapeutic reversibility of CEPT1 deficits and safety of lipid restoration strategies remain to be established
Future Directions: Test CEPT1 restoration or phosphatidylcholine supplementation in translational models; evaluate ER stress/mitochondrial protectants; validate CEPT1 as a biomarker in longitudinal asthma cohorts.
Asthma is associated with disordered glycerophospholipid metabolism and decreased phosphatidylcholine (PC), but the molecular basis remains incompletely defined. Through integrative data mining, we identify CEPT1, a key enzyme in glycerophospholipid biosynthesis, to be significantly downregulated in the airway epithelium of asthma. CEPT1 deficiency causes PC/PE reduction and phospholipid imbalance, activates all three endoplasmic reticulum (ER) stress pathways, disturbs ER Ca
2. Astrocyte activation in the ventrolateral medulla modulates breathing and arousal states.
In alert mice, Aldh1l1 astrocytes in the ventral respiratory column activate prior to sighs and during hypoxia, and their opto/chemogenetic activation increases arousals coupled to sighs. Astrocyte activation augments calcium transients in neighboring catecholaminergic neurons, revealing an astrocyte–neuronal mechanism for hypoxia-evoked ventilatory and arousal responses.
Impact: It identifies astrocytes as active modulators of sigh-linked arousal in the ventrolateral medulla, advancing the cellular circuitry of respiratory–arousal coupling under hypoxia.
Clinical Implications: Targeting astrocyte–catecholaminergic signaling in the ventrolateral medulla could inform therapies for disordered arousal in sleep-disordered breathing, sudden infant death vulnerability, or hypoxia-related arousal deficits.
Key Findings
- A subset of Aldh1l1 astrocytes in the ventral respiratory column activates prior to sigh generation and is recruited by hypoxia.
- Chemogenetic/optogenetic activation of these astrocytes increases the probability of arousals coupled with sighs.
- Astrocyte activation enhances calcium transients in catecholaminergic neurons immediately before arousal-with-sigh events.
Methodological Strengths
- Causal manipulation via chemogenetics and optogenetics in alert behaving mice
- Simultaneous calcium imaging linking astrocyte activation to neuronal dynamics and behavior
Limitations
- Findings are in mice; translational relevance to human respiratory control needs validation
- Focus on sigh-associated arousals; broader respiratory phenotypes and disease models were not tested
Future Directions: Dissect astrocyte receptor pathways and gliotransmitters mediating catecholaminergic recruitment; test roles in sleep-disordered breathing and sudden death models; explore pharmacologic modulators.
Astrocytes play vital roles in regulating brain states across organisms. Specifically, they regulate breathing behaviors and associated brain states, including facilitating transitions between breathing phases by sensing changes in O₂ and CO₂ levels, regulating the sleep-wake cycle, and impacting arousal and wakefulness. Here, we test the hypothesis that astrocytes in the ventral respiratory column (VRC) are important for arousal and sigh generation in alert mice. Our results reveal that a subset of Aldh1l1 cells in the VRC are activated prior to sigh generation and are recruited by hypoxia. Chemogenetic or optogenetic activation of Aldh1l1 astrocytes in the VRC increased the probability of evoking arousals with sighs. We also demonstrated that activating Aldh1l1 astrocytes increased calcium transients in catecholaminergic neurons in the VRC immediately before arousal with sighs. We conclude that medullary astrocytes can modulate sigh generation and arousal transitions, and are important for the ventilatory and arousal response to hypoxia.
3. Modelling the impact of long-acting monoclonal antibody, maternal vaccine and hybrid programs of RSV immunisation in temperate Western Australia.
A dynamic model calibrated to Western Australia hospitalizations shows that all RSV programs reduce burden, with newborn nirsevimab averting more hospitalizations than maternal vaccine at equal coverage. Seasonal and high-risk–targeted strategies minimize number-needed-to-immunize, and hybrid programs may mitigate cost differentials while retaining strong impact.
Impact: It provides first comprehensive evidence to design hybrid RSV immunization programs optimizing type, timing, and targeting, directly informing policy and economic evaluations.
Clinical Implications: Programs prioritizing seasonal peaks and high-risk infants, with hybrid deployment of maternal vaccine and nirsevimab, can maximize hospitalization prevention while improving affordability; findings support local timing and coverage decisions.
Key Findings
- At similar coverage, newborn nirsevimab programs avert more RSV hospitalizations than maternal vaccination alone.
- Seasonal and high-risk–targeted programs achieve the lowest number needed to immunize to prevent one hospitalization.
- Hybrid programs can offset cost differentials between products while maintaining high effectiveness.
Methodological Strengths
- Dynamic transmission model calibrated to age-specific hospitalization data in the target setting
- Scenario analysis across timing, coverage, and risk-targeting with consideration of dose cost
Limitations
- Model assumptions (e.g., duration of protection, mixing patterns) may not generalize beyond the setting
- Formal cost-effectiveness analyses were not completed and require country-specific inputs
Future Directions: Integrate real-world effectiveness and waning data for both products; perform full cost-effectiveness across jurisdictions; evaluate operational feasibility and equity impacts of hybrid roll-outs.
BACKGROUND: Two RSV immunisations products: a maternal vaccine, Abrysvo, and a long-acting monoclonal antibody, nirsevimab, both designed to prevent RSV illness in infants, have recently become available. Modelling evidence is required to inform how to optimally use these products in immunisation programs to reduce the burden of RSV in young children. METHODS: We extend a dynamic transmission model calibrated to RSV-hospitalisation data of children aged <5 years in temperate Western Australia (WA) to simulate a range of potential RSV immunisation programs. Using our model, we estimate the impact of both single-product and hybrid RSV immunisation programs. The analysis considers timing of administration, coverage levels and targeting of high-risk groups. Impact on RSV burden is analysed in the context of the WA setting and the possible significant cost differences between the two products. RESULTS: All programs analysed were effective in reducing RSV burden. Programs using nirsevimab for newborn infants at similar coverage levels to the Abrysvo programs, averted more RSV-hospitalisations annually. Seasonal programs that focused on protection during high RSV activity and programs targeting high-risk infants had the lowest number needed to immunise to avert one RSV-hospitalisation. When dose cost is considered alongside program impact on RSV burden, we find evidence to support further economic analysis of hybrid programs as they could mitigate the cost differential between the two products while remaining highly effective in reducing RSV burden. CONCLUSIONS: Our study is the first to comprehensively analyse hybrid RSV immunisation programs that use Abrysvo and nirsevimab. RSV immunisation programs can substantially reduce the burden of RSV in young children. Our modelling analysis provides evidence on immunisation type, timing, coverage, high-risk groups and dosage cost that will support decision makers and can be used in economic evaluations.