Monthly ReportJun 1–30, 2025
Sepsis, June 2025 edition
We read 81 papers and selected 5.
Summary
June 2025 sepsis research showed a clear shift toward precision immunology, endothelial and organ-specific mechanisms, and implementation-ready diagnostics. Mechanistic studies identified actionable inflammatory circuits, including PGK1-NLRP3, endothelial CLEC5A, TNF-caspase-8 pyroptosis, and lactylation of HADHA in septic cardiomyopathy. Large human cohorts and multi-cohort transcriptomic analyses advanced pathogen-informed classification, immune endotyping, and prognostic biomarkers such as the SoM signature and EV-CLB. In parallel, rapid blood-culture diagnostics, antimicrobial stewardship, decolonisation policy, and device coatings emphasized practical approaches to reduce time to effective therapy and thromboinflammatory complications.
Selected Articles
1. Endothelial CLEC5A drives barrier dysfunction and vascular leakage responsible for lung injury in bacterial pneumonia and sepsis.
Using CLP and LPS mouse models, the study demonstrated that endothelial CLEC5A causally promotes vascular leakage, cytokine amplification, lung injury, and mortality. Endothelial-specific knockdown improved survival, while endothelial re-expression reversed the benefit. Single-cell RNA sequencing further characterized endothelial changes associated with CLEC5A activity.
Impact: The study identifies a cell-type-specific and therapeutically tractable driver of endothelial barrier failure, a central mechanism of sepsis-associated lung injury.
Clinical Implications: CLEC5A-blocking antibodies or antagonists could potentially limit vascular leakage and lung injury. Human tissue validation, pharmacodynamic studies, and evaluation of infection-control risks are needed.
Key Findings
- Clec5a-deficient mice showed reduced mortality in CLP and LPS sepsis models.
- Endothelial-specific CLEC5A knockdown improved survival, whereas endothelial re-expression abolished protection.
- CLEC5A deficiency reduced cytokine amplification and vascular leakage and altered endothelial transcriptomic states.
2. Lactylation of HADHA Promotes Sepsis-Induced Myocardial Depression.
This mechanistic study identified extensive lysine lactylation in septic myocardium and demonstrated that lactylation at HADHA K166 and K728 inhibits HADHA activity. The resulting mitochondrial dysfunction and reduced ATP production impaired cardiomyocyte contractility. SIRT1 and SIRT3 regulated these modifications, and site-directed experiments confirmed causal effects in cellular and LPS/CLP sepsis models.
Impact: The study provides a direct molecular link between lactate accumulation and septic cardiomyopathy, while identifying a potentially druggable HADHA-SIRT1/SIRT3 axis.
Clinical Implications: Modulating lactylation or SIRT1/SIRT3 activity may become a strategy to preserve myocardial mitochondrial function in sepsis. Translation will require validation in human septic myocardium, pharmacologic specificity studies, and assessment of cardiovascular safety.
Key Findings
- A total of 1,127 lysine lactylation sites were mapped, including 83 differentially lactylated sites in sepsis.
- HADHA K166 and K728 lactylation impaired enzymatic activity, mitochondrial function, ATP production, and cardiomyocyte contractility.
- SIRT1 and SIRT3 regulated HADHA lactylation, and site-directed mutagenesis supported causality in vivo and in vitro.
3. Pathogen-specific host response in critically ill patients with blood stream infections: a nested case-control study.
In a multi-cohort study of 341 patients, the causative pathogen explained 41.8% of blood transcriptomic variance. Streptococcal bloodstream infection generated a validated 8-gene host-response classifier, while Escherichia coli and Staphylococcus aureus showed distinct inflammatory and endothelial activation profiles. The findings support pathogen-informed precision diagnostics in bloodstream infection and sepsis.
Impact: It combines human multi-cohort evidence with an externally validated small-gene classifier, creating a practical bridge between host-response biology and pathogen-directed care.
Clinical Implications: A rapid version of the classifier could help infer pathogen class before culture results are finalized and support earlier antimicrobial targeting. Analytical validation, turnaround-time assessment, and prospective clinical-impact studies are required.
Key Findings
- The causative pathogen accounted for 41.8% of blood transcriptomic variance.
- An externally validated 8-gene classifier identified streptococcal bloodstream infection.
- E. coli and S. aureus bloodstream infections showed distinct cytokine and endothelial activation patterns.
4. A conserved immune dysregulation signature is associated with infection severity, risk factors prior to infection, and treatment response.
Across 12,026 blood samples from 68 cohorts, this study validated a conserved 42-gene Severe-or-Mild (SoM) immune signature. The score linked age, sex, obesity, smoking, and comorbidity with infection severity, mortality, and differential response to hydrocortisone. It establishes a framework for immune-based patient stratification and precision immunotherapy.
Impact: The scale and cross-cohort validation make SoM one of the strongest candidates for biologically informed sepsis stratification and treatment selection.
Clinical Implications: SoM could help identify patients who may benefit from or be harmed by corticosteroids and could enrich clinical trials for likely responders. Prospective testing is required before routine bedside use.
Key Findings
- A 42-gene SoM signature was associated with pre-infection risk factors and infection severity.
- SoM predicted mortality and identified patients potentially harmed by hydrocortisone.
- The signature was modifiable by immunomodulatory drugs and lifestyle-related interventions across cohorts.
5. In situ self-growth nano-selenium hydrogel coating alleviates surface thrombosis of blood-contacting devices by inactivating inflammatory cells.
This study developed an in situ self-growing nano-selenium hydrogel coating that reprogrammed macrophages toward an anti-inflammatory phenotype, reduced tissue-factor release and thrombin generation, and suppressed catheter thrombosis. Effects were observed in vitro, rabbit and pig vascular models, and translational observations involving septic patients. The platform links device engineering with immunomodulation of thromboinflammation.
Impact: The platform addresses a common ICU problem—device-associated thrombosis—through a mechanism-based coating with evidence spanning cellular, animal, and translational settings.
Clinical Implications: If selenium exposure, durability, biocompatibility, and infection risks are acceptable, the coating could reduce catheter-related thromboinflammation in septic patients. Controlled human studies are required before clinical adoption.
Key Findings
- The coating increased the M2/M1 macrophage ratio by 146% and reduced proinflammatory cytokine activity.
- It reduced tissue-factor release and thrombin generation under septic inflammatory conditions.
- Catheter and vascular models showed reduced thrombosis and inflammatory activation.