Daily Sepsis Research Analysis
Mechanistic and translational advances dominated today’s sepsis literature. A basic study reveals that microvesicle-transferred mitochondria activate cGAS-STING and reprogram macrophage metabolism, suggesting new anti–cytokine storm targets. Clinically, a neonatal RCT shows probiotics reduce ventilator-associated pneumonia and resource use, while a preclinical study identifies Sigma-1 receptor agonism as a potential therapy for sepsis-associated encephalopathy.
Summary
Mechanistic and translational advances dominated today’s sepsis literature. A basic study reveals that microvesicle-transferred mitochondria activate cGAS-STING and reprogram macrophage metabolism, suggesting new anti–cytokine storm targets. Clinically, a neonatal RCT shows probiotics reduce ventilator-associated pneumonia and resource use, while a preclinical study identifies Sigma-1 receptor agonism as a potential therapy for sepsis-associated encephalopathy.
Research Themes
- Innate immune sensing and immunometabolism in sepsis (cGAS-STING, mitochondrial transfer)
- Infection prevention in critical neonates via microbiome modulation (probiotics)
- Neuroinflammation targeting in sepsis-associated encephalopathy (Sigma-1 receptor)
Selected Articles
1. Microvesicle-transferred mitochondria trigger cGAS-STING and reprogram metabolism of macrophages in sepsis.
Microvesicles from LPS-primed macrophages transfer mitochondria to recipient macrophages, activating cGAS-STING signaling and altering inflammatory cytokine expression and cellular metabolism. Multimodal assays (TEM, immunofluorescence, RT-qPCR, metabolomics) support a mechanism linking mitochondrial transfer to cytokine storm amplification in sepsis.
Impact: Identifies a previously underappreciated intercellular mechanism—mitochondrial transfer via microvesicles—linking innate immune sensing (cGAS-STING) to immunometabolic reprogramming in sepsis.
Clinical Implications: Therapeutic strategies targeting microvesicle biogenesis, mitochondrial transfer, or cGAS-STING activation could mitigate cytokine storm and organ injury in sepsis.
Key Findings
- Microvesicles from LPS-primed macrophages transfer mitochondria to recipient macrophages.
- Transferred mitochondria activate cGAS-STING signaling in recipient cells.
- Inflammatory cytokine expression increases and cellular metabolism is reprogrammed, as supported by immunofluorescence, RT-qPCR, and metabolomics.
Methodological Strengths
- Multimodal validation (TEM imaging, immunofluorescence, RT-qPCR, metabolomics).
- Mechanism-focused design directly linking organelle transfer to innate immune pathway activation.
Limitations
- Abstract indicates primarily in vitro/ex vivo assessments; in vivo validation details are not provided.
- Translational applicability and safety of targeting mitochondrial transfer remain to be established.
Future Directions: Test inhibitors of microvesicle biogenesis or cGAS-STING in relevant in vivo sepsis models and evaluate organ protection and survival; dissect metabolic nodes amenable to pharmacologic modulation.
The inflammatory cytokine storm is a hallmark of sepsis and is highly correlated with organ injury. Therefore, inhibiting inflammatory cytokine production is a straightforward strategy for effectively treating this disease. In this study, we found that microvesicles from lipopolysaccharide (LPS)-primed macrophages could transfer mitochondria to other macrophages and alter their biological functions. Microvesicles were isolated from LPS-primed macrophages and characterized by transmission electron microscopy. The function of microvesicle-transferred mitochondria in macrophages was evaluated by assessing the expression levels of inflammatory cytokines using immunofluorescent and quantitative real-time polymerase chain reaction (RT-qPCR) assays, and metabonomics using
2. Assessment of the role of probiotics in prevention of ventilator-associated pneumonia in neonates.
In a single-center randomized controlled trial of 80 ventilated neonates, probiotic supplementation reduced VAP incidence (20% vs 47.5%; OR 0.28), decreased feeding intolerance and GI symptoms, and shortened both ventilation duration (by 10 days) and NICU stay (by 8 days). Findings support probiotics as an adjunctive VAP prevention strategy in NICUs.
Impact: Provides randomized evidence in a vulnerable population with clinically meaningful reductions in infection and resource utilization.
Clinical Implications: NICUs may consider probiotic prophylaxis protocols for ventilated neonates, with careful selection of strains and monitoring for safety, to reduce VAP and associated morbidity.
Key Findings
- VAP incidence was lower with probiotics: 20% vs 47.5% (OR 0.28, 95% CI 0.10–0.75).
- Reductions in feeding intolerance (17.5% vs 44.0%), vomiting (12.5% vs 40.0%), and abdominal distension (10.0% vs 44.0%).
- Shorter mechanical ventilation (mean difference 10 days) and shorter NICU stay (mean difference 8 days) in the probiotic group.
Methodological Strengths
- Prospective randomized controlled design with prespecified outcomes.
- Clinically relevant endpoints (VAP incidence, ventilation duration, NICU length of stay).
Limitations
- Single-center trial with modest sample size and unclear blinding.
- Probiotic formulation details (strain/CFU) are incomplete in the abstract.
Future Directions: Conduct multicenter, blinded RCTs defining specific strains/doses and safety profiles, and assess generalizability across NICU settings and preterm populations.
PURPOSE: Ventilator-associated pneumonia (VAP) is a severe complication in NICUs. It increases morbidity, mortality, and healthcare costs. The research purpose was to evaluate the preventive value of probiotics on the incidence of VAP among ventilated neonates. METHODS: This prospective randomized controlled study was done at the NICU of Tanta University Hospitals for one year. Eighty full-term neonates who required invasive mechanical ventilation for over 48 h were randomly divided into a probiotic group (n = 40) and a non-probiotic group (n = 40). Besides the standard treatment that was given to both groups, the probiotic group received a sachet containing 1 × 10 RESULTS: The incidence of VAP was significantly lower in the probiotics group (20%) compared to the non-probiotic group (47.5%) with an OR of 0.28 (95% CI: 0.10-0.75). Additionally, administration of probiotics was associated with a significantly lower incidence of feeding intolerance, vomiting, and abdominal distension (17.5%, 12.5%, and 10.0% vs. 44.0%, 40.0%, and 44.0% in probiotic and non-probiotic groups, respectively) with OR = 0.26, 0.21, and 0.18, respectively. On the other hand, there was a significantly shorter duration of mechanical ventilation in the probiotic group over the non-probiotic group (MD = 10 days, 95% CI: 6.30-13.70). Similarly, NICU stay was significantly shorter in the probiotic group compared to the non-probiotic group (MD = 8 days, 95% CI: 3.29-12.71). Conclusion Probiotics seem to be effective in the prevention of VAP among mechanically ventilated neonates. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov/ NCT07001163; registered May 23, 2025. WHAT IS KNOWN: • VAP is a common and serious nosocomial infection in mechanically ventilated neonates, associated with prolonged hospitalization and increased mortality • Current VAP preventive strategies focus on infection control and supportive care measures • In neonatal care, probiotics have shown efficacy in reducing necrotizing enterocolitis (NEC) and late-onset sepsis incidence in preterms What is new: • Probiotics have shown potential in enhancing mucosal barrier function, competing with pathogenic bacteria, and supporting systemic immune responses. Therefore, probiotic supplementation could have clinical efficacy in the prevention of VAP in NICUs.
3. Sigma-1 receptor activation by PRE-084 attenuates sepsis-associated encephalopathy by targeting microglial p38 MAPK-mediated neuroinflammation and neuronal endoplasmic reticulum stress.
In a CLP mouse model, the Sigma-1R agonist PRE-084 improved survival and neurological outcomes, reduced neuronal ER stress (BiP, p-eIF2α), preserved PSD95, and suppressed neuroinflammation by inhibiting microglial p38 MAPK signaling and lowering TNF-α/IL-6. Results position Sigma-1R as a tractable target for SAE.
Impact: Connects neuronal ER stress mitigation to secondary suppression of microglial p38 MAPK-driven neuroinflammation, improving survival and cognition in sepsis.
Clinical Implications: Sigma-1R agonists warrant translational evaluation for SAE; dosing, timing, and safety require careful clinical trial design.
Key Findings
- PRE-084 improved survival and neurological performance in CLP-induced sepsis.
- Reduced neuronal ER stress (lower BiP and p-eIF2α) and preserved synaptic protein PSD95.
- Suppressed neuroinflammation via decreased microglial/astrocyte activation and inhibition of microglial p38 MAPK, lowering TNF-α and IL-6.
Methodological Strengths
- Use of a clinically relevant CLP model with multimodal behavioral, molecular, and survival endpoints.
- Mechanistic dissection linking neuronal ER stress to microglial p38 MAPK signaling.
Limitations
- Preclinical mouse study; human efficacy and safety remain unknown.
- Single agonist and model; dose-response and therapeutic window characterization are needed.
Future Directions: Validate Sigma-1R agonism across sepsis models, define PK/PD and therapeutic windows, and initiate early-phase trials focusing on neurocognitive outcomes in SAE.
BACKGROUND: Sepsis-Associated Encephalopathy (SAE) is a severe neurological complication of sepsis, where neuroinflammation plays a critical pathogenic role, leading to cognitive dysfunction. The Sigma-1 receptor (Sigma-1R), a chaperone protein, is implicated in neuroprotection, including the crucial modulation of neuroinflammation and endoplasmic reticulum stress (ERS). This study aimed to investigate the therapeutic potential of the Sigma-1R agonist, PRE-084, in specifically targeting SAE-associated neuroinflammation and its downstream neuropathology. METHODS: A cecal ligation and puncture (CLP) murine model of sepsis was established. Mice received the Sigma-1R agonist PRE-084 or saline. Neurological function (SHIRPA), survival rates, and cognitive performance (Morris Water Maze) were assessed. Hippocampal and cortical tissues were analyzed for Sigma-1R expression and localization, ERS markers (BiP, p-eIF2α), synaptic protein levels (PSD95, Synaptophysin), glial cell activation (Iba-1, GFAP), pro-inflammatory cytokine levels (TNF-α, IL-6), and p38 Mitogen-Activated Protein Kinase (p38 MAPK) pathway activation using Western blotting, immunofluorescence, and ELISA. RESULT: CLP surgery induced neurological deficits, reduced survival, and upregulated neuronal Sigma-1R in the hippocampus. PRE-084 administration significantly improved survival rates, ameliorated neurological impairments, and attenuated cognitive dysfunction in CLP mice. Mechanistically, PRE-084 treatment directly mitigated neuronal CLP-induced ERS (reduced BiP expression and eIF2α phosphorylation) and preserved hippocampal postsynaptic density protein 95 (PSD95) levels. Crucially, these primary neuroprotective effects on neurons translated into a profound suppression of neuroinflammation, evidenced by reduced microglial (Iba-1) and astrocyte (GFAP) activation, decreased brain levels of pro-inflammatory cytokines TNF-α and IL-6, and specific inhibition of microglial p38 MAPK activation. This indicates an indirect but potent anti-inflammatory effect stemming from primary neuronal Sigma-1R engagement. CONCLUSION: Our findings demonstrate that activation of neuronal Sigma-1R by PRE-084 confers protection against SAE. This protection involves primary mitigation of neuronal ERS, which is pivotal in subsequently dampening the detrimental microglial p38 MAPK-mediated neuroinflammatory cascade. This multifaceted action, culminating in reduced neuroinflammation, improves neurological outcomes and cognitive function. Targeting Sigma-1R to control neuroinflammation offers a promising therapeutic strategy for SAE.