Daily Sepsis Research Analysis
Analyzed 47 papers and selected 3 impactful papers.
Summary
Three studies advance sepsis science across mechanism and infrastructure: (1) a mechanistic discovery shows PEAR1 drives endothelial metabolic-epigenetic feedback via AARS1-mediated HIF-1α lactylation, increasing lung permeability and mortality in septic mice; (2) a national, prospective APS Consortium demonstrates rapid, large-scale phenotyping with high biospecimen capture; (3) mechanobiology work shows neutrophil Piezo1 senses pathological strain, escalating NETs and acute lung injury. Together they reveal targetable biology and enable future precision trials.
Research Themes
- Endothelial metabolic-epigenetic feedback and vascular permeability in sepsis-induced lung injury
- Mechanobiology of neutrophils: Piezo1, mitochondrial stress, and NETs in acute lung injury
- National platform for high-resolution phenotyping and biobanking in ARDS/pneumonia/sepsis
Selected Articles
1. PEAR1 Promotes Glucose Metabolism Reprogramming in Sepsis-Associated Acute Lung Injury via AARS1-Mediated HIF-1α Lactylation.
In septic mice, endothelial PEAR1 drives AARS1-mediated HIF-1α K172 lactylation, boosting glycolysis, enhancing nuclear translocation, and creating a lactate–histone lactylation positive feedback that increases vascular permeability. Genetic Pear1 loss and endothelial-targeted Pear1 siRNA liposomes ameliorated lung injury and improved survival in polymicrobial sepsis.
Impact: This study identifies a previously unreported HIF-1α lactylation site and a PEAR1-centered metabolic-epigenetic feedback loop linking endothelial signaling to barrier failure and mortality, revealing tractable targets for S-ALI.
Clinical Implications: Endothelial-targeted strategies that inhibit PEAR1 signaling or lactylation machinery (e.g., AARS1/EP300 axis) may reduce pulmonary permeability and improve outcomes in sepsis-induced lung injury; translational development of targeted delivery is warranted.
Key Findings
- PEAR1 expression and vascular permeability were elevated in septic mouse lungs; Pear1 knockdown reduced permeability and lung injury.
- PEAR1 promoted AARS1-mediated HIF-1α lactylation at K172, facilitating importin-α binding, nuclear translocation, and glycolysis; lactate increased H3K18 lactylation at the Pear1 promoter, forming a positive feedback loop.
- Pear1 knockout and endothelial-targeted Pear1 siRNA liposomes ameliorated ALI and improved survival in polymicrobial sepsis.
Methodological Strengths
- Multi-level mechanistic mapping with genetic knockdown/knockout, biochemical PTM identification, and endothelial-targeted delivery in vivo
- Demonstration of a novel HIF-1α lactylation site (K172) and functional validation in survival-relevant models
Limitations
- Preclinical mouse models; human endothelial validation and safety of targeted delivery were not established.
- Quantitative survival effect sizes and dose–response for the liposomal siRNA approach were not detailed in the abstract.
Future Directions: Validate PEAR1–AARS1–lactylation axis in human tissues and biospecimens, develop selective inhibitors or RNA therapeutics with endothelial targeting, and assess pharmacology and safety in larger animal models.
Sepsis-associated acute lung injury (S-ALI), in which pulmonary microvascular endothelial cells act as key drivers of disease progression by increasing vascular permeability and ultimately exacerbating lung injury, is associated with a high mortality rate. Here, we report that PEAR1 expression and vascular permeability are increased in the lung tissues of septic mice. Pear1 knockdown markedly reduces pulmonary vascular permeability and consequently attenuates lung injury in septic mice. Mechanistically, PEAR1 promotes the AARS1-mediated lactylation of HIF-1α, primarily at lysine 172 (K172). This lactylation event, in turn, increases the affinity of HIF-1α for importin α, thereby facilitating HIF-1α nuclear translocation. Importantly, HIF-1α K172 lactylation promotes glycolysis, and glycolysis-derived lactate further drives H3K18 lactylation. In addition, this lactate-dependent histone modification is enriched at the Pear1 promoter, resulting in further increases in glycolysis and pulmonary vascular permeability. In vivo, both Pear1 knockout and the targeted delivery of Pear1 siRNA to inflammatory vascular endothelial cells using E-selectin-binding peptide-modified liposomes ameliorate ALI, and improve survival in mice with polymicrobial sepsis. Our study identifies K172 as a previously unreported lactylation site on HIF-1α and shows that PEAR1 promotes AARS1-mediated HIF-1α lactylation, enhances glycolysis, and increases H3K18la enrichment at the Pear1 promoter, thereby forming a positive feedback loop.
2. The ARDS, Pneumonia, and Sepsis (APS) Consortium: Rationale, Design, and Feasibility of a National Platform for Phenotyping Critical Illness Syndromes.
A national, prospective multicenter cohort enrolled 1,000 critically ill adults with high severity ahead of schedule, with excellent biospecimen capture across compartments. Expert adjudication confirmed high proportions of sepsis (89%), pneumonia (52%), and ARDS (40%), demonstrating feasibility for large-scale, biology-first phenotyping.
Impact: Establishes a scalable platform with rich longitudinal data and biospecimens to define biologically coherent sepsis/ARDS/pneumonia subphenotypes, enabling target discovery and adaptive trial designs.
Clinical Implications: While not immediately practice-changing, APS will accelerate biomarker validation, endotype-driven trials, and precision enrollment strategies that can translate into improved patient stratification and outcomes.
Key Findings
- First 1,000 participants enrolled in <13 months with high acuity: 75% on vasopressors, 50% mechanically ventilated, 25% in-hospital mortality within 4 weeks.
- High biospecimen capture: blood 99%, upper respiratory swabs 98%, lower respiratory 37%, urine 80%, GI 65%.
- Expert adjudication: 89% sepsis, 52% pneumonia, 40% ARDS among enrolled participants.
Methodological Strengths
- Prospective multicenter design with predefined phenotyping protocol and expert adjudication
- High-yield, multi-compartment biobanking enabling multi-omics and longitudinal analyses; trial registration (NCT06521502)
Limitations
- Feasibility phase; clinical interventions and outcome-improving strategies are not yet tested.
- Lower respiratory sample yield (37%) may limit deep lung analyses in some participants.
Future Directions: Complete enrollment to 4,000, integrate multi-omics to define treatable traits, and embed adaptive, phenotype-guided interventional trials within the platform.
BACKGROUND: To enhance biological understanding of acute respiratory distress syndrome (ARDS), pneumonia, and sepsis and accelerate therapeutic development in these areas, the National Institutes of Health developed the ARDS, Pneumonia, and Sepsis (APS) Consortium. RESEARCH QUESTION: Is the APS Consortium study rapidly generating data and biospecimens from a large cohort of critically ill adults with ARDS, pneumonia, and sepsis that will facilitate phenotyping of these syndromes? STUDY DESIGN AND METHODS: The APS Consortium Phenotyping Study is a multicenter longitudinal prospective observational cohort study aimed at enrolling 4,000 critically ill adults with ARDS, pneumonia, and/or sepsis over 4 years. Data and biospecimens are collected to characterize many aspects of each participant's chronic health, acute illness, and long-term recovery to facilitate phenotyping-that is, subclassifying ARDS, pneumonia, and sepsis into precise biologically-based subsets with shared pathophysiology. Feasibility of the study was assessed by evaluating the first 1,000 participants in terms of recruitment pace, participant characteristics, biospecimen collection, and proportion with confirmed ARDS, pneumonia, and sepsis based on expert adjudication. RESULTS: The first 1,000 participants were recruited ahead of schedule in less than 13 months. Median age was 64 years, 75% received vasopressors, 50% received invasive mechanical ventilation, and 25% died in the hospital within 4 weeks of enrollment. Biospecimen collection rates were high, with 99% of participants with blood, 98% with upper respiratory swabs, 37% with lower respiratory samples, 80% with urine, and 65% with gastrointestinal samples. Expert adjudication resulted in 40% classified with ARDS, 52% with pneumonia, and 89% with sepsis. INTERPRETATION: The APS Consortium Phenotyping Study is producing a cohort of critically ill adults with ARDS, pneumonia, and sepsis with high severity of disease and a rich set of data and biospecimens. The study will continue to full enrollment of 4,000 participants. REGISTRATION: Clinicaltrials.gov NCT06521502.
3. Mechanical stress promotes excessive NETs and exacerbates acute lung injury via Piezo1-mediated mitochondrial dysfunction.
Using in vivo mechanical ventilation and in vitro compression models, the study shows that neutrophil Piezo1 senses pathological strain, drives cytosolic Ca2+ signaling, mitochondrial damage, and excessive NETs, thereby worsening ALI. scRNA-seq revealed a distinct mechanosensitive, mitochondrial-stress PMN cluster expanding during injury.
Impact: Reveals a mechanotransduction pathway in neutrophils linking lung biomechanics to mitochondrial dysfunction and NETs, providing testable targets (Piezo1, mechanomodulation) to mitigate ventilator-related and sepsis-associated lung injury.
Clinical Implications: Findings support rational oxygenation/ventilation strategies that minimize pathological strain and motivate evaluation of Piezo1 modulation to reduce NET-driven injury in ALI secondary to sepsis or ventilation.
Key Findings
- Neutrophil Piezo1 senses pathological mechanical strain, triggering cytosolic Ca2+ signaling and pro-inflammatory activation.
- A mechanosensitive, mitochondrial-stress PMN cluster with elevated ROS expands during ALI, identified by single-cell RNA sequencing.
- Mechanical stress promotes excessive NET formation that exacerbates ALI in sequential LPS and differential ventilation models.
Methodological Strengths
- Integration of in vivo mechanical ventilation and in vitro compression systems with single-cell transcriptomics
- Mechanistic linkage from mechanosensing (Piezo1) to mitochondrial dysfunction and effector (NETs) biology
Limitations
- Preclinical models; human validation of Piezo1-dependent NETs in clinical ALI is needed.
- Therapeutic Piezo1 inhibition or mechanomodulatory interventions were not tested for outcome improvement.
Future Directions: Test Piezo1 inhibitors or biomechanical ventilation strategies to attenuate NET-mediated injury; validate mechanosensitive PMN states and biomarkers in human sepsis/ALI cohorts.
Acute lung injury (ALI) is a respiratory insufficiency syndrome precipitated by factors such as infection, sepsis, or systemic trauma. Excessive polymorphonuclear neutrophil (PMN) infiltration and activation represent the hallmark cellular features of early-stage ALI. However, it remains poorly understood how the pulmonary biomechanical microenvironment, remodeled by ALI-induced diffuse edema, decreased lung compliance, and mechanical ventilation, modulates PMN hyperactivation. Using a sequential model of LPS-induced lung injury and differential mechanical ventilation combined with an in vitro cell compression system, we demonstrate that PMN Piezo1 senses pathological physical strain and orchestrates pro-inflammatory responses. Single-cell RNA sequencing identified a mechanosensitive "mitochondrial-stress" PMN cluster that expands during ALI, defined by profound mitochondrial damage and elevated ROS production. Mechanistically, Piezo1 transduces mechanical stimuli into cytosolic Ca