Daily Sepsis Research Analysis
Analyzed 51 papers and selected 3 impactful papers.
Summary
Mechanistic studies advanced understanding of sepsis immunopathology and organ injury. HDAC1 was identified as a driver of CD8+ T-cell exhaustion in sepsis with pharmacologic inhibition improving survival in mice, while a splenic norepinephrine–β2-adrenergic receptor axis aggravated sepsis-associated acute kidney injury via neutrophil-mediated immunosuppression. A multi-therapy single-cell liver atlas mapped compound-specific rebalancing of inflammatory networks, informing rational multitarget strategies.
Research Themes
- T-cell exhaustion and epigenetic regulation in sepsis
- Neuro-immune splenic signaling driving kidney injury in sepsis
- Single-cell atlas of sepsis-induced liver injury under multimodal therapies
Selected Articles
1. HDAC1 modulates sepsis-induced immunosuppression by driving the exhaustion of CD8+ T cells.
This study identifies HDAC1 as a key epigenetic driver of CD8+ T-cell exhaustion in sepsis. Pharmacologic HDAC1 inhibition restored T-cell function, rebalanced AP-1/NFAT signaling, and improved survival in murine sepsis, highlighting a tractable immunomodulatory target.
Impact: Reveals a novel, targetable mechanism of sepsis-induced immunosuppression linking HDAC1 to NFAT1-driven inhibitory programs, with in vivo survival benefit upon inhibition.
Clinical Implications: Suggests HDAC1 inhibitors as candidates for reversing T-cell exhaustion in septic patients, warranting translational studies to define dosing, timing, and safety.
Key Findings
- CD8+ T-cell depletion in septic patients correlated with worse outcomes; exhausted CD8+ T cells increased in murine lungs by scRNA-seq.
- HDAC1 expression was upregulated in septic patient CD8+ T cells; inhibition reduced PD-1 and preserved T-cell function.
- Pharmacologic HDAC1 inhibition improved survival and reversed exhaustion by restoring AP-1/NFAT balance.
- HDAC1 directly interacted with NFAT1, promoting its nuclear translocation and inhibitory molecule expression.
Methodological Strengths
- Integrated clinical patient data with murine scRNA-seq, adoptive transfer, and pharmacologic intervention
- Mechanistic validation of protein interaction (HDAC1–NFAT1) alongside functional immune phenotyping
Limitations
- Preclinical efficacy demonstrated in mice; no human interventional data
- Potential off-target effects and safety profile of HDAC1 inhibition in sepsis remain undefined
Future Directions: Translate to early-phase clinical trials testing HDAC1 inhibitors in sepsis, with biomarker-guided selection and pharmacodynamic endpoints for T-cell exhaustion.
Sepsis, a systemic inflammatory response to infection, remains a leading cause of mortality in intensive care units, with sepsis-induced immunosuppression being a critical pathophysiological process. In this study, we investigated the role of histone deacetylase 1 (HDAC1) in sepsis-induced CD8+ T cell exhaustion, a key driver of immunosuppression. Clinical analyses of patients with sepsis revealed that reduced peripheral blood lymphocyte levels, particularly CD8+ T cell depletion, strongly correlated with worsened outcomes. In a murine sepsis model, single-cell RNA-Seq revealed a significant decrease in the proportion of CD8+ T cells and an increase in the proportion of exhausted CD8+ T cells in mouse lungs. Adoptive transfer of CD8+ T cells effectively reduced sepsis mortality by preserving organ function. We further demonstrated that HDAC1 expression was significantly upregulated in CD8+ T cells from patients with sepsis. In vitro studies showed that HDAC1 inhibition preserved CD8+ T cell function by maintaining T cell activity and reducing the expression of inhibitory molecules such as PD-1. Pharmacological inhibition of HDAC1 reduced mortality and reversed CD8+ T cell exhaustion by restoring the balance between activator protein-1 (AP-1) and nuclear factor of activated T cells (NFAT). Additionally, we found that HDAC1 directly interacted with NFAT1, promoting its nuclear translocation and further enhancing the expression of inhibitory molecules. Our findings highlight HDAC1 as a potential therapeutic target for sepsis-induced immunosuppression. By elucidating the molecular mechanisms underlying HDAC1-mediated immunosuppression, we have provided potential strategies for developing immunomodulatory therapies for the treatment of sepsis.
2. The splenic norepinephrine-β2-adrenergic receptor axis aggravates sepsis-associated acute kidney injury via neutrophil-mediated immunosuppression.
Splenic norepinephrine–β2-adrenergic signaling in neutrophils suppresses Th1 responses via PGE2 and worsens SA-AKI; interrupting this axis through denervation or β2-AR blockade improved survival and kidney injury in sepsis models.
Impact: Identifies a neuro-immune splenic pathway that can be targeted to ameliorate sepsis-induced kidney injury, supported by single-cell data and genetic/neural interventions.
Clinical Implications: Supports evaluation of organ-specific β2-adrenergic modulation to restore antimicrobial immunity and protect kidneys in sepsis, while recognizing systemic β-blockade risks.
Key Findings
- Splenic denervation mitigated sepsis-induced kidney injury, while intrasplenic norepinephrine exacerbated damage in CLP mice.
- Splenic β2-AR blockade improved survival and reduced kidney injury.
- Neutrophil-specific Adrb2 knockout and local neutrophil depletion implicated splenic neutrophils as mediators.
- Mechanistically, NE/β2-AR signaling increased neutrophil PGE2 via CREB, suppressing Th1 activation and increasing local infections.
Methodological Strengths
- Convergent evidence from neural manipulation, genetic knockout, and single-cell sequencing
- Organ- and cell-specific interventions with survival and functional endpoints
Limitations
- Pre-emptive denervation is not directly translatable to clinical practice
- Lack of human validation; findings based on murine CLP models
Future Directions: Assess pharmacologic modulation of splenic β2-AR signaling and PGE2 pathways in translational sepsis models; explore targeted delivery approaches.
INTRODUCTION: Sepsis-associated acute kidney injury (SA-AKI) is frequently complicated by immune paralysis and kidney infection. Despite the spleen's critical immunological role, the neural mechanisms regulating the splenic immune responses during SA-AKI remain unclear. METHODS: To examine this, we used splenic denervation, continuous intrasplenic infusion, single-cell sequencing and neutrophil-specific β2 adrenergic receptor Adrb2 knockout mice to define the role of the splenic norepinephrine-β2-adrenergic receptor (NE/β2-AR) axis in SA-AKI. RESULTS: Our findings indicate that pre-emptive splenic denervation in mice mitigates sepsis-induced kidney injury, whereas local intrasplenic norepinephrine infusion exacerbates kidney damage in a cecal ligation/puncture (CLP) mouse model. Targeted blockade of splenic β2-adrenergic receptor (β2-AR) signaling enhances survival and attenuates kidney damage in CLP mice. Local splenic depletion of neutrophil and neutrophil-specific conditional knockout of Adrb2 demonstrates that NE/β2-AR signaling influences splenic neutrophils, thereby driving the progression of acute sepsis. Mechanistic investigations reveal that splenic NE/β2-AR signaling enhances neutrophil prostaglandin E2 synthesis via the cAMP-response element binding protein pathway, thereby suppressing T helper 1 cell activation, increasing local bacterial infections, and aggravating SA-AKI. CONCLUSIONS: These findings clarify the role of splenic NE/β2-AR signaling in modulating neutrophil-mediated immunosuppression, thereby driving sepsis progression and aggravating kidney damage.
3. A multitherapy single-cell atlas reveals cell type-specific modulation in sepsis-induced liver injury.
An integrative single-cell atlas of septic murine liver delineates shared and compound-specific immunomodulation by artesunate, capsaicin, and oridonin. Therapies suppress neutrophil expansion via distinct regulons, reprogram endothelium, dampen CCL signaling, and enhance regenerative cues.
Impact: Provides a high-resolution cellular framework linking candidate anti-inflammatory compounds to specific immune modules in septic liver, informing rational multitarget therapy design.
Clinical Implications: Identifies tractable immune circuits (e.g., CCL axis, endothelial NF-κB/oxidative stress, EGF signaling) that could be co-targeted to rebalance hepatic immunity in sepsis.
Key Findings
- Defined treatment-responsive neutrophil subtypes (Ngp+ Neu1, Cd274+ Neu2, Stfa2l1+ Neu4) with all three therapies suppressing neutrophil expansion via distinct regulons.
- Documented endothelial reprogramming in sepsis (NF-κB activation, oxidative stress) selectively modulated by each therapy.
- Revealed convergent dampening of inflammatory ligand–receptor networks, including the CCL axis, and therapy-specific enhancement of regenerative EGF signaling.
- Macrophage activation and infiltration contributed to partial immune homeostasis rebalancing.
Methodological Strengths
- Cross-condition integration of multiple single-cell datasets with cell–cell communication analysis
- Comparative mechanistic mapping across three distinct anti-inflammatory compounds
Limitations
- Reanalysis synthesizes existing murine datasets without new in vivo validation for each prediction
- Translational relevance to human sepsis requires confirmation
Future Directions: Experimentally test predicted ligand–receptor and regulon targets (e.g., CCL axis, endothelial NF-κB) and evaluate combination regimens guided by the atlas.
Sepsis-induced liver injury involves profound immune dysregulation. Natural compounds such as artesunate (ART), capsaicin (CAP), and oridonin (ORI) have demonstrated efficacy in mitigating systemic inflammation; however, their comparative cellular mechanisms in sepsis remain poorly characterized. Here, we integrated and reanalyzed the single-cell transcriptomic datasets of murine livers from 5 conditions: healthy control, sepsis, and sepsis treated with ART, CAP, or ORI. We uncover a spectrum of neutrophil subtypes with treatment-responsive phenotypes, including anti-inflammatory Ngp+ Neu1, immunosuppressive Cd274+ Neu2, and mature Stfa2l1+ Neu4, in which the excessive neutrophil expansion was suppressed by all 3 therapies through distinct regulon activities. Macrophages were activated and infiltration to partially rebalance immune homeostasis. Endothelial cells underwent profound reprogramming under sepsis, marked by NF-κB activation and oxidative stress, which are selectively modulated by treatment. Cell-cell communication analysis revealed a convergent dampening of inflammatory ligand-receptor networks, including the CCL signaling axis, and therapy-specific enhancement of regenerative cues, such as EGF signaling. Our findings reveal both shared and compound-specific immunoregulatory effects of ART, CAP, and ORI, offering mechanistic insights into hepatic immune rebalancing in sepsis. This single-cell atlas provides a conceptual framework for the rational design of multitarget therapies and highlights the key immune modules amenable to therapeutic intervention.