Daily Sepsis Research Analysis
Analyzed 28 papers and selected 3 impactful papers.
Summary
Analyzed 28 papers and selected 3 impactful articles.
Selected Articles
1. Death-associated protein kinase 2 (DAPK2) propagates endoplasmic reticulum stress in macrophages to worsen sepsis through HSPA5-IRE1α axis.
The study uncovers a macrophage-intrinsic DAPK2–HSPA5–IRE1α axis that amplifies ER stress and worsens sepsis. DAPK2 phosphorylates HSPA5 at Ser588, promoting its degradation and downstream IRE1α activation; genetic DAPK2 deletion mitigates disease.
Impact: It identifies a mechanistic pathway linking innate immune signaling to ER stress with clear molecular nodes (DAPK2, HSPA5, IRE1α) that are targetable, advancing sepsis immunobiology.
Clinical Implications: Therapeutic strategies that inhibit DAPK2 kinase activity or stabilize HSPA5 to limit IRE1α overactivation could attenuate harmful macrophage ER stress in sepsis.
Key Findings
- DAPK2 is upregulated in sepsis macrophages via TLR4–MyD88–NF-κB signaling.
- Macrophage-specific DAPK2 deletion reduces ER stress and sepsis severity in mice.
- DAPK2 phosphorylates HSPA5 at Ser588, promoting HSPA5 degradation and IRE1α activation.
- HSPA5 inhibition worsens sepsis in DAPK2-deficient mice, reversed by IRE1α deactivation.
Methodological Strengths
- Multi-system validation: human septic macrophages, septic mouse models, and macrophage-specific gene deletion
- Mechanistic depth with LC-MS/MS interactome mapping and site-specific phosphorylation with functional rescue
Limitations
- Preclinical models without clinical intervention trials or pharmacologic DAPK2 inhibition in humans
- Potential variability across infection sources and sepsis endotypes not fully explored
Future Directions: Develop selective DAPK2 inhibitors or HSPA5-stabilizing agents; validate axis activation in clinical sepsis cohorts and assess cell type–specific effects across infection phenotypes.
Sepsis is associated with a pronounced but poorly understood endoplasmic reticulum stress (ERS) response. In this study, we found that death-associated protein kinase 2 (DAPK2), a calcium/calmodulin-regulated serine/threonine kinase, exhibits elevated expression in macrophages from patients with sepsis and from septic mice. Macrophage DAPK2 expression is transcriptionally upregulated through the activation of the Toll-like receptor 4 (TLR4)-myeloid differentiation primary response 88 (MyD88)-nuclear factor-κB (NF-κB) pathway. Macrophage-specific deletion of DAPK2 attenuated sepsis severity and mitigated the ERS response. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified heat shock protein family A member 5 (HSPA5) as a binding partner for DAPK2. Because DAPK2 function had been previously associated with the kinase activity, we speculated that it might control ERS of macrophages through HSPA5 phosphorylation. Further investigation indeed revealed that DAPK2 phosphorylates HSPA5 at serine-588, which promotes the proteasomal degradation of HSPA5 and subsequently leads to the activation of inositol-requiring enzyme 1α (IRE1α). Inhibition of HSPA5 exacerbated sepsis in mice with macrophage-specific DAPK2 deficiency; however, this effect was abrogated by the deactivation of IRE1α. In conclusion, our findings demonstrate that DAPK2 propagates macrophage ERS through the HSPA5-IRE1α axis during systemic infection, suggesting this pathway as a potential therapeutic target in sepsis.
2. Targeting inflammation and coagulation: MMP-9 deficiency exacerbates sepsis induced acute lung injury through fibrinogen-driven inflammation.
Through multi-omics integration and experimental validation, MMP9 was identified as a causal protective factor in sepsis-induced acute lung injury, likely via interaction with fibrinogen that links coagulation and inflammation. MMP9 deficiency worsened injury in vivo, supporting its role as a potential early biomarker and therapeutic node.
Impact: It integrates human genomics, causal inference (MR), computational modeling, and animal validation to position MMP9 at the coagulation–inflammation interface, advancing biomarker and target discovery for sepsis-induced lung injury.
Clinical Implications: Early measurement of MMP9 may aid risk stratification in sepsis-related lung injury, and therapeutic strategies should consider preserving or augmenting beneficial MMP9 activity rather than indiscriminate inhibition.
Key Findings
- Multi-omics pipeline and two-sample Mendelian randomization identified MMP9 as a causal protective gene in sepsis-induced lung injury.
- Molecular docking and 100 ns molecular dynamics suggest a specific MMP9–fibrinogen interaction linking coagulation and inflammation.
- In vivo CLP models with MMP9 deficiency exhibited exacerbated lung injury, supporting a protective role and biomarker potential.
Methodological Strengths
- Causal inference via two-sample Mendelian randomization combined with transcriptomics and PPI network analysis
- Cross-validation with computational docking/MD and in vivo CLP models for mechanistic and functional corroboration
Limitations
- Abstracted sample sizes and full in vivo effect sizes are not reported; external clinical validation is pending
- MR assumptions (no pleiotropy) and docking predictions require orthogonal confirmation in human tissues
Future Directions: Prospective validation of MMP9 as a lung injury biomarker in sepsis cohorts; interventional studies probing MMP9–fibrinogen modulation; development of assays suitable for clinical deployment.
Sepsis is caused by a dysregulated host response to infection, characterized by multiorgan failure in which the lung is the primary target. Although matrix metalloproteinase-9 (MMP9), a macrophage-derived protease, is known to degrade extracellular matrix proteins during inflammation, its specific role in sepsis-induced lung injury (SALI) remains to be elucidated. This study elucidates the protective function of MMP9 in SALI and validated its translational potential as an early diagnostic biomarker that integrates coagulation-inflammation crosstalk. First, we integrated human blood bulk RNA-seq data and an in-house LPS-induced murine ALI model to extract coagulation-related sepsis DEGs (Cos-Gs), constructed a PPI network, and applied two-sample Mendelian randomization (MR), which identified MMP9 as a causal protection gene. Additionally, we performed molecular docking using the ZDOCK server and 100 ns molecular dynamics simulations with Gromacs to explore the interaction between MMP9 and fibrinogen. Next, in vivo studies using CLP-operated MMP9
3. Re-evaluating the 14-day rule: short-course antifungal therapy for uncomplicated candidaemia in a multicentre cohort study.
In 203 adults with uncomplicated candidaemia achieving rapid clearance and source control, 7–13 days of antifungal therapy was not associated with higher mortality or recurrence versus 14–20 days after IPTW adjustment. Findings were consistent across mortality and recurrence endpoints up to one year.
Impact: Challenges a long-standing 14-day treatment convention using multicenter data and causal adjustment, with potential to reduce drug exposure, costs, and toxicity without compromising outcomes.
Clinical Implications: For carefully selected uncomplicated candidaemia with documented clearance and source control, clinicians can consider 7–13 days of therapy, coupled with diligent follow-up and exclusion of deep-seated foci.
Key Findings
- Short-course (7–13 days) antifungal therapy showed no increase in EOT 14-day mortality versus 14–20 days after IPTW adjustment.
- EOT 90-day recurrence was low (4.4%) with no significant difference between groups; secondary outcomes up to 1 year were similar.
- Cohort restricted to microbiological clearance within 5 days and adequate source control, enhancing internal validity.
Methodological Strengths
- Multicenter cohort with clear inclusion criteria for 'uncomplicated' candidaemia
- Robust confounding control using IPTW with consistent sensitivity and subgroup analyses
Limitations
- Retrospective design with potential residual confounding and selection bias
- Modest sample size and single-country setting may limit generalizability
Future Directions: Prospective randomized trials to confirm non-inferiority of short-course therapy and to refine criteria for 'uncomplicated' candidemia across diverse settings.
OBJECTIVES: Current guidelines recommend at least 14 days of antifungal therapy for uncomplicated candidaemia after blood culture clearance, despite limited supporting evidence. We evaluated whether antifungal treatment duration was associated with clinical outcomes. METHODS: This multicentre retrospective study in Taiwan (January 2014 to June 2024) included adults with uncomplicated candidaemia (microbiological clearance within 5 days, adequate source control, and no deep-seated or metastatic infection) completing 7-20 days of antifungal therapy. Patients were classified into short-course (7-13 days) and long-course (14-20 days) groups. Primary outcomes were all-cause mortality within 14 days and recurrence within 90 days after the end of treatment (EOT) and secondary outcomes were EOT 90-day mortality and EOT 1-year recurrence. Inverse probability of treatment weighting (IPTW) was applied to adjust for confounders. RESULTS: Among 203 patients, 72 (35.5%) received short-course and 131 (64.5%) long-course therapy. Overall, EOT 14-day mortality was 7.4% (5.6% versus 8.4% in short-course and long-course groups, respectively). Short-course therapy was not associated with increased EOT 14-day mortality in crude (OR 0.64, 95% CI 0.17-1.95), multivariable (aOR 0.33, 95% CI 0.06-1.35), or IPTW-weighted analyses (aOR 0.42, 95% CI 0.11-1.55). The EOT 90-day recurrence rate was 4.4%, with no significant differences across analyses. IPTW-weighted Kaplan-Meier and subgroup analyses showed consistent findings. No significant differences were observed in secondary outcomes, including EOT 90-day mortality and EOT 1-year recurrence. CONCLUSIONS: Short-course antifungal therapy was not associated with increased mortality or recurrence compared with long-course therapy among patients with uncomplicated candidaemia who achieved adequate source control and microbiological clearance.