The inflammatory response in sepsis

Impact of antiplatelet therapy on outcomes of sepsis: A systematic review and meta-analysis

OBJECTIVE

Antiplatelet therapy has been studied for its potential benefits in various cardiovascular conditions, but its role in sepsis remains less clear. This review aims to systematically analyse the available evidence on the effects of antiplatelet therapy in sepsis to assess its potential benefits and risks.

MATERIAL AND METHODS

The studies published until 01st April 2024 from PubMed, Embase and Scopus databases were searched. Pooled effect sizes were reported as relative risks (RR) or weighted mean difference (WMD) with corresponding 95% confidence intervals (CI). Outcomes included mortality, length of intensive care unit (ICU) stay, hospital stay, and the risk of complications. The certainty of evidence was evaluated using GRADE.

RESULTS

Twenty-one studies were included. Antiplatelet therapy was associated with significantly lower risk of in-hospital mortality (RR 0.76, 95% CI: 0.67, 0.87), and mortality at one (RR 0.77, 95% CI: 0.66, 0.90) and three months (RR 0.77, 95% CI: 0.66, 0.90) follow up. Risk of complications was comparable in all patients (RR 1.01, 95% CI: 0.84, 1.21). ICU stay (in days) (WMD -0.23, 95% CI: -0.53, 0.07; N=7, I2=97.2%) and overall duration of hospital stay (in days) (WMD 0.63, 95% CI: -0.66, 1.92; N=6, I2=93.2%) was also statistically similar among patients who received and did not receive antiplatelet drugs. The certainty of evidence for the outcomes ranged from "low to very low".

CONCLUSION

Antiplatelet therapy appears safe and significantly lowers the risk of short-term mortality in septic patients. While antiplatelet therapy did not impact the duration of ICU or overall hospital stay, our findings underscore the potential of antiplatelet agents as a beneficial adjunctive therapy in sepsis management.

Targeting the immuno-inflammatory-microbial network: a key strategy for sepsis treatment

Sepsis is a life-threatening condition caused by a dysregulated host response to infection, remaining a major global health challenge despite clinical advances. Therapeutic challenges arise from antibiotic misuse, incomplete understanding of its complex pathophysiology, and the unresolved interplay of immune dysregulation and microbiota disruption. Investigating microbial homeostasis in the shift from cytokine storm to immunosuppression may elucidate the interplay between microbial metabolites, immune dysfunction, and organ injury, providing a foundation for targeted therapies and drug development. Traditional Chinese Medicine (TCM) has demonstrated significant advantages in mitigating sepsis-associated cytokine storms and modulating gut microbiota homeostasis, offering a promising strategy for developing highly effective and less toxic targeted monomeric compounds. Elucidating the interactions within the immune-inflammation-microbiota network in sepsis paves the way for biomarker-driven personalized therapeutic approaches.

Proper early weaning from ventilator assistance influences the overall survival of patients with severe burns: A case-control study

BACKGROUND

Ventilator assistance is crucial in the treatment of severely burned patients. However, there is no consensus on the optimal duration of ventilator assistance, and whether it has an impact on the short - and long-term prognosis of severely burned patients is still unclear.

METHODS

We incorporated 185 severely burned patients in our study. Kaplan-Meier analysis and Chi-square tests were applied to reveal the associations of days of ventilator assistance with patients' overall survival (OS) and other clinical variables. Multivariable Cox regression was applied, and the model was diagnosed by residual analysis, calibration curve analysis, decision curve analysis, and receiver operating characteristic curve analysis. 144 burned patients in Changhai Cohort were used for external validation.

RESULTS

Ventilator assistance >26 days was significantly associated with a shorter OS in severely burned patients (P-value <0.001). Besides, "days of ventilator assistance" was significantly correlated with the burn area (P-value <0.001), and the combination of inhalation injury (P-value <0.01), sepsis, DIC, AHF, AKI, ALF, and ARDS (P-value <0.001). The prognostic value of "days of ventilator assistance" was further validated in Changhai Cohort.

CONCLUSION

Prolonged ventilator assistance was associated with decreased OS in severely burned patients. Under the premise of the recovery of spontaneous respiratory function, early weaning from ventilator assistance might improve the prognosis of patients with severe burns. The findings on the optimal duration of ventilator assistance and its impact on survival in severely burned patients would interest healthcare professionals in respiratory and critical care medicine.

Farnesoid X Receptor Regulated Sepsis-Induced Abnormal Bile Acid Metabolism via the Fibroblast Growth Factor 15/Fibroblast Growth Factor Receptor 4 Pathway

OBJECTIVE

The study aims to investigate the mechanism of Farnesoid X receptor (FXR) activation in sepsis-induced abnormal bile acid metabolism and the metabolism status of each bile acid type.

METHODS

The sepsis mouse model was developed via lipopolysaccharide intraperitoneal injection and confirmed via hematoxylin and eosin (H&E) staining. FXR agonist activated the FXR/fibroblast growth factor (FGF)15/FGFR pathway via quantitative real-time polymerase chain reaction and Western blot. Consequently, metabolomics and bioinformatics analysis were conducted to identify the alterations in each kind of bile acid content following FXR agonist/inhibitor intervention.

RESULTS

The H&E staining indicated that FXR activation alleviates the liver injury of the sepsis mouse model. The increased FGF15 and FXFR expression levels and decreased CYP7A1 demonstrated FXR/FGF15/FGFR pathway activation following FXR agonist treatment. Furthermore, total bile acid, interleukin (IL)-6, and tumor necrosis factor-α concentrations were downregulated after FXR activation, whereas IL-10 concentration was upregulated, indicating the alleviated effect of FXR agonist in sepsis. Consequently, metabolomics and bioinformatics analysis determined that T-a-MCA were downregulated in both FXR agonist and inhibitor groups, whereas six bile acid types were altered in the control group.

CONCLUSION

FXR activation was crucial in alleviating sepsis-induced hepatic injury and cholestasis through the FGF15/FGFR signaling pathway, and FXR may act as a potential preventive and intervention target of sepsis.

Multi-omics analysis reveals that low cathepsin S expression aggravates sepsis progression and worse prognosis via inducing monocyte polarization

Background

Monocytes represent a vital cellular subpopulation in the peripheral blood, crucial in the progression of sepsis. Nonetheless, the prognostic role and precise function of monocytes in sepsis are still inadequately understood.

Methods

Single-cell transcriptomic sequencing and bioinformatics analysis were performed on peripheral blood samples from septic patients to identify key molecules in cell subsets. Subsequently, the expression pattern of this molecule was validated through diverse biological experiments, encompassing quantitative RT-PCR, western blotting, and immunofluorescence. Finally, the functionality of this molecule was evaluated using its specific agonist.

Results

A total of 22 monocytes-related biomarkers were identified from single-cell and bulk RNA-seq analyses. Initially, LASSO analysis was performed to derive a prognostic signature composed of 4 key genes, including CD14, CTSS, CXCL8 and THBS1. Subsequently, mendelian randomization and survival analysis demonstrated that only CTSS showed crucially protective role in sepsis development and prognosis. Next, CTSS was confirmed to be lower expressed in peripheral monocytes of septic patients. Inflammatory markers (p < 0.05) and migration ability of LPS-activated monocytes were significantly reduced after CTSS agonist. In addition, CTSS agonist decreased the pulmonary tissue monocyte/macrophages infiltration in septic mice.

Conclusion

Monocyte marker CTSS represent a promising target for the diagnosis and prognosis evaluation of sepsis and plays a critical role in monocytes activation, tissue inflammatory response and macrophages infiltration. Thus, CTSS agonist probably serves as new drug for clinical protection against sepsis.

The protective role of kakkalide in sepsis-induced intestinal barrier dysfunction via inhibition of NF-κB pathway activation

Sepsis, a systemic inflammatory response often triggered by infection, can lead to multi-organ failure, with the intestine being one of the most vulnerable organs. The nuclear factor kappa-B (NF-κB) pathway plays a crucial role in immune responses, inflammation, and cell survival, making it central to sepsis-induced intestinal damage. Kakkalide (KA), a bioactive compound known for its anti-inflammatory, cardiovascular, neuroprotective, and anti-diabetic properties, has potential therapeutic effects. However, its impact on sepsis-induced intestinal injury remains unclear. In this study, murine sepsis models were used both in vivo and in vitro to evaluate the protective effects of KA on intestinal histopathology, apoptosis, and inflammation. Results showed that KA significantly reduced intestinal damage and apoptosis, as evidenced by hematoxylin-eosin and TUNEL staining. KA also improved intestinal barrier integrity, as indicated by reduced diamine oxidase activity, d-lactic acid content, and fluorescein isothiocyanate intensity, along with increased expression of zonula occludens-1. Furthermore, KA alleviates inflammation by reducing the levels of tumor necrosis factor-α, interleukin-1β, prostaglandin E2, inducible nitric oxide synthase, and cyclooxygenase-2. Immunofluorescence and Western blot analysis revealed that KA inhibited the sepsis-induced phosphorylation of inhibitor-kappaBα and RelA (P65) and prevented P65's translocation to the nucleus. These findings were confirmed in lipopolysaccharide-induced Caco-2 cells, suggesting that KA protected the intestinal barrier during sepsis by suppressing the NF-κB pathway.

Phellodendrine Exerts Protective Effects on Intra-abdominal Sepsis by Inactivating AKT/NF-kB Signaling

Acute kidney injury (AKI) and acute lung injury (ALI) are major complications of intra-abdominal sepsis, leading to increased mortality. Phellodendrine (PHE) is a characteristic and important active ingredient of Phellodendri Cortex, possessing multiple pharmacological properties. This study intends to explore the effect of PHE on intra-abdominal sepsis-induced AKI and ALI. An intra-abdominal infection-induced rat model of sepsis was established by fecal intraperitoneal injection, followed by the administration of PHE. ELISA was used to determine plasma levels of inflammatory cytokines. Hematoxylin-eosin, Periodic acid Schiff, and Masson trichrome staining were employed for histopathological analysis of rat kidney and lung tissues. Western blotting was used to estimate the AKT/NF-κB signaling-related protein levels. The results showed that PHE improved the survival rate of septic rats and reduced plasma levels of proinflammatory cytokines. PHE administration attenuated pathological lesions in the kidneys and lungs of septic rats. Mechanistically, PHE treatment blocked AKT/NF-κB signaling in septic rats' kidneys and lungs. In conclusion, PHE ameliorates intra-abdominal sepsis-induced kidney and lung injury possibly by inactivating AKT/NF-kB signaling.

The Efficacy and Safety of Continuous Veno-Venous Hemodiafiltration With High Cutoff Membrane Versus High Flux Membrane in Septic Acute Kidney Injury: A Randomized Controlled Study

BACKGROUND

The application of high cutoff (HCO) membranes for continuous renal replacement therapy remains unclear in septic acute kidney injury (S-AKI) patients.

METHODS

S-AKI patients who received continuous veno-venous hemodiafiltration (CVVHDF) were randomly assigned to the experimental group (HCO membrane) and the control group (high flux membrane, HF membrane). Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in serum and waste fluid were measured at 0, 2, 12, and 24 h after CVVHDF initiation and the 28-day mortality.

RESULTS

Eleven patients were randomized to the HCO group, and 9 patients in the HF group, with a mean age of 54.9 ± 3.2 years and 6 patients (30%) being female. After 24 h of treatment with CVVHDF, there were significant reductions in serum IL-6 and TNF-α concentrations in the HCO group (p = 0.001, 0.015) and HF group (p = 0.004, 0.031). The serum IL-6 reduction rate of the HCO group was significantly higher than that of the HF group (79.21% vs. 42.69%, p = 0.025), while serum TNF-α reduction rates were comparable between the 2 groups. There were no significant changes in serum albumin after 24 h using either HCO membrane (28.7 ± 1.7 g/L vs. 32.7 ± 1.6 g/L, p = 0.138) or HF membrane (29.6 ± 1.1 g/L vs. 32.6 ± 1.3 g/L, p = 0.055). The two groups had similar 24-h filter clotting rates and 28-day mortality.

CONCLUSION

While CVVHDF with the HCO membrane and HF membrane both achieved significant reductions in serum cytokine levels, the HCO membrane was associated with a greater reduction rate in IL-6 but not in TNF-α. No difference was observed in serum albumin, mortality, or filter clotting.

TRIAL REGISTRATION

Registry number: ChiCTR2000039725.

Multifunctional nanoparticles confers both multiple inflammatory mediators scavenging and macrophage polarization for sepsis therapy

Sepsis is a serious and life-threatening condition, which can lead to organ failure and death clinically. Abnormally increased cell-free DNA (cfDNA) and inflammatory cytokines are involved in the development and progression of sepsis. Thus, cfDNA clearance and down-regulation of inflammatory factors are essential for the effective treatment of sepsis. Here we designed and constructed a polydopamine-based multifunctional nanoparticle for the treatment of sepsis. These nanoparticles (NPs) are composed of polydopamine (PDA) grafted with cationic polyethyleneimine (PEI). On the one hand, the NPs can utilize the electrostatic interaction to effectively adsorb cfDNA in blood, then effectively inhibiting the activation of toll like receptors (TLRs) and nuclear factor kappa B (NF-κB) pathways induced by cfDNA. On the other hand, the NPs have an immunomodulatory function, which can effectively convert pro-inflammatory macrophage (M1) into anti-inflammatory macrophage (M2), thus reduce the release of inflammatory cytokines and slow down the inflammatory storm of sepsis. In addition, the NPs possess good reactive oxygen species (ROS) scavenging ability. Briefly, the effective treatment of sepsis can be achieved by multiple strategies of effectively capturing the inflammatory triggering factor cfDNA, modulating the polarization of M1 macrophage to M2 macrophage and scavenging ROS, which has a promising clinical application.

Is there a place for natural agents with anti-inflammatory and antioxidative properties in critically ill patients? Potential usefulness of Xanthohumol

Multi-organ dysfunction is a major issue in critically ill patients, where a significant inflammatory response appears to be the primary factor driving the degree of organ impairment, which correlates with the extent of organ injury. The management of inflammation requires a multidisciplinary approach, including antibiotics for infection control, circulatory and respiratory support, and correction of coagulation abnormalities. However, the use of anti-inflammatory treatments is typically restricted to a selected group of medications, with their effectiveness remaining the subject of extensive debate. Xanthohumol (Xn), a natural compound extracted from hops, possesses strong anti-inflammatory and antioxidative properties, with a mild anti-coagulation effect. Its biological activity is related to the inhibition of different inflammatory pathways, reduction in cytokine production and secretion, and an increase in antioxidative enzyme activity. This review examined the potential use of Xn as an adjuvant in the treatment of various pathologies in critically ill patients.

Identification of DNA damage repair-related genes in sepsis using bioinformatics and machine learning: An observational study

Sepsis is a life-threatening disease with a high mortality rate, for which the pathogenetic mechanism still unclear. DNA damage repair (DDR) is essential for maintaining genome integrity. This study aimed to explore the role of DDR-related genes in the development of sepsis and further investigated their molecular subtypes to enrich potential diagnostic biomarkers. Two Gene Expression Omnibus datasets (GSE65682 and GSE95233) were implemented to investigate the underlying role of DDR-related genes in sepsis. Three machine learning algorithms were utilized to identify the optimal feature genes. The diagnostic value of the selected genes was evaluated using the receiver operating characteristic curves. A nomogram was built to assess the diagnostic ability of the selected genes via "rms" package. Consensus clustering was subsequently performed to identify the molecular subtypes for sepsis. Furthermore, CIBERSORT was used to evaluate the immune cell infiltration of samples. Three different expressed DDR-related genes (GADD45A, HMGB2, and RPS27L) were identified as sepsis biomarkers. Receiver operating characteristic curves revealed that all 3 genes showed good diagnostic value. The nomogram including these 3 genes also exhibited good diagnostic efficiency. A notable difference in the immune microenvironment landscape was discovered between sepsis patients and healthy controls. Furthermore, all 3 genes were significantly associated with various immune cells. Our findings identify potential new diagnostic markers for sepsis that shed light on novel pathogenetic mechanism of sepsis and, therefore, may offer opportunities for potential intervention and treatment strategies.

Identification of lethality-related m7G methylation modification patterns and the regulatory features of immune microenvironment in sepsis

Objectives

N7-methylguanosine (m7G) modification is closely related to the occurrence of human diseases, but its roles in sepsis remain unclear. This study aimed to explore the patterns of lethality-related m7G regulatory factor-mediated RNA methylation modification and immune microenvironment regulatory features in sepsis.

Methods

Three sepsis-related datasets (E-MTAB-4421 and E-MTAB-4451 as training sets and GSE185263 as a validation set) were collected, and differentially expressed m7G-related genes were analyzed between survivors and non-survivors. Lethality-related m7G signature genes were then screened using machine learning methods, followed by the construction of a survival recognition model. Additionally, differences in immune cell distribution were determined and differentially expressed genes (DEGs) between different subtypes were analyzed. Weighted gene co-expression network analysis (WGCNA) was used to select important modules and related hub genes.

Results

In total, 10 differentially expressed m7G-related genes were identified between the survivors and non-survivors, and after further analysis, EIF4G3, EIF4E3, NSUN2, NUDT4, and GEMIN5 were identified as the optimal lethality-related m7G genes. A survival status diagnostic model was then constructed with a combined AUC of 0.678. Fifteen types of immune cells were significantly different between survivors and non-survivors. Sepsis samples were classified into two subtypes, with 22 types of immune cells showing significant differences. Subsequently, 1707 DEGs were identified between the two subtypes, which were significantly enriched in 91 GO terms and 16 KEGG pathways. Finally, the green module with |correlation| > 0.3 was found to be closely related to the subtypes and survival status; further, the top10 hub genes were obtained.

Conclusion

The constructed survival status diagnostic model based on the five lethality-related m7G signature genes may help predict the survival status of patients, and the 10 hub genes obtained may be potential therapeutic targets for sepsis.

Systemic inflammatory response index improves prognostic predictive value in intensive care unit patients with sepsis

Sepsis is a severe infectious disease with high mortality. However, the indicators used to evaluate its severity and prognosis are relatively complicated. The systemic inflammatory response index (SIRI), a new inflammatory indicator, has shown good predictive value in chronic infection, stroke, and cancer. The purpose of this study was to investigate the connection between sepsis and SIRI and evaluate its predictive usefulness. A total of 401 patients with sepsis were included in this study. Multiple linear regression and logistic regression analyses were performed to evaluate the relationship between SIRI and sepsis. The restricted cubic spline (RCS) method was employed to illustrate the dose-response relationship. The area under the curve (AUC) and decision curve analysis (DCA) were used to evaluate the prognostic value of SIRI. Multiple linear regression analysis revealed a significant positive correlation between SIRI and both blood cell count and Sequential Organ Failure Assessment (SOFA) score. Additionally, higher SIRI levels were significantly linked to a higher risk of sepsis worsening, according to logistic regression analysis. The RCS curve demonstrated that the risk of poor prognosis rose with increasing SIRI, particularly when SIRI exceeded 6.1. Furthermore, AUC and DCA results showed that SIRI had superior predictive value compared to traditional indicators. A higher SIRI is linked to a worse prognosis and more severe sepsis. SIRI may serve as a novel prognostic indicator in sepsis, though further clinical studies are necessary to confirm these findings.

Overexpression of ALKBH5 alleviates LPS induced neuroinflammation via increasing NFKBIA

Sepsis-associated encephalopathy (SAE) is a serious condition in which the immune system uncontrollably responds to infection, causing organ dysfunction. Neuroinflammation is one of the primary mechanisms underlying SAE. N6-methyladenosine (m6A) methylation is a common and reversible chemical modification of RNA molecules. Increasing evidence suggests that this modification plays a vital role in the inflammatory immune response. AlkB homolog 5 (ALKBH5) is an enzyme responsible for removing m6A modifications from RNA molecules and is known as a demethylase. However, the specific role of ALKBH5 in neuroinflammation remains unclear. To explore the role of ALKBH5 in neuroinflammation, researchers have used lipopolysaccharide (LPS) to induce inflammation in BV2 cells and mice. This study found that treatment of BV2 cells with LPS (1 μg/mL) significantly increased the total RNA m6A level and the ALKBH5 protein decreased significantly. Meanwhile, the NF-κB inflammatory signaling pathway was activated, leading to an obvious increase in IL-1β, IL-6, and TNF-α mRNA. The LPS-induced inflammatory response was alleviated when ALKBH5 was overexpressed in BV2 cells. This is due to a slower degradation rate of NFKBIA mRNA, an increase in NFKBIA protein levels, and inhibition of the NF-κB inflammatory signal pathway. When ALKBH5 was overexpressed in mice, as expected, there was an improvement in behavioral abnormalities induced by LPS. Compared to healthy volunteers, ALKBH5 mRNA levels were significantly decreased in peripheral blood mononuclear cells (PBMCs) from patients with sepsis and correlated with GCS and IL-6 levels. In summary, this study suggested that ALKBH5 is a potential therapeutic target for enhancing NFKBIA mRNA stability and alleviating neuroinflammation. Thus, ALKBH5 may provide new insights into the diagnosis and treatment of SAE.

Immune-cell signatures of persistent inflammation, immunosuppression, and catabolism syndrome after sepsis

BACKGROUND

Management of persistent inflammation, immunosuppression, and catabolism syndrome (PICS) after sepsis remains challenging for patients in the intensive care unit, experiencing poor quality of life and death. However, immune-cell signatures in patients with PICS after sepsis remain unclear.

METHODS

We determined immune-cell signatures of PICS after sepsis at single-cell resolution. Murine cecal ligation and puncture models of PICS were applied for validation.

FINDINGS

Immune functions of two enriched monocyte subpopulations, Mono1 and Mono4, were suppressed substantially in patients with sepsis and were partially restored in patients with PICS after sepsis and exhibited immunosuppressive and pro-apoptotic effects on B and CD8T cells. Patients with PICS and sepsis had reduced naive and memory B cells and proliferated plasma cells. Besides, naive and memory B cells in patients with PICS showed an active antigen processing and presentation gene signature compared to those with sepsis. PICS patients with better prognoses exhibited more active memory B cells and IGHA1-plasma cells. CD8TEMRA displayed signs of proliferation and immune dysfunction in the PICS-death group in contrast with the PICS-alive group. Megakaryocytes proliferation was more pronounced in patients with PICS and sepsis than in healthy controls, with notable changes in the anti-inflammatory and immunomodulatory effects observed in patients with PICS and verified in mice models.

CONCLUSIONS

Our study evaluated PICS after sepsis at the single-cell level, identifying the heterogeneity present within immune-cell subsets, facilitating the prediction of disease progression and the development of effective intervention.

FUNDING

This work was supported by the National Natural Science Foundation of China, Shanghai Municipal Health Commission "Yiyuan New Star" Youth Medical Talent Cultivating Program, and Shanghai Clinical Research Center for Anesthesiology.

Downregulation of HSPA12A protects heart against sepsis through suppressing mTOR-mediated inflammatory response in cardiomyocytes

OBJECTIVE

Over-activated immune response in hearts is the main pathological feature of septic cardiomyopathy, a fatal complication of sepsis with high mortality. Autophagy is capable to limit immune response by removing inflammatory mediators. Heat shock protein A12A (HSPA12A) encodes an atypical member of HSP70 family. This study aimed to investigate the role of HSPA12A in septic cardiomyopathy.

METHODS

Sepsis was induced by cecal ligation and puncture (CLP) for 6 h in mice in vivo or by LPS treatment for 24 h in primary cardiomyocytes in vitro. HSPA12A knockout (Hspa12a-/-) mice were generated by cre-loxp system. Echocardiography was performed to assess cardiac function. TUNEL and propidium iodide (PI) staining was used to indicate cardiomyocyte death. Inflammation-related factors were examined by qPCR and immunoblotting. Autophagy was evaluated by levels of LC3-II and p62.

RESULTS

Sepsis decreased HSPA12A expression in hearts and cardiomyocytes, while HSPA12A knockout in mice attenuated sepsis-induced cardiomyocyte death and cardiac dysfunction. Sepsis-induced activation of TLR4/MyD88/NF-κB-mediated inflammation was inhibited in hearts by HSPA12A knockout whereas was enhanced by HSPA12A overexpression in cardiomyocytes. Moreover, HSPA12A overexpression activated mTOR and inhibited autophagy in cardiomyocytes, while inhibition of mTOR by rapamycin diminished the HSPA12A-induced autophagy inhibition, inflammation activation, and cardiomyocyte death in septic cardiomyocytes.

CONCLUSION

Downregulation of HSPA12A inhibited mTOR to activated autophagy, thereby suppressed inflammatory response, and ultimately attenuated septic cardiomyopathy. Our findings identified HSPA12A as a driver for septic cardiomyopathy development, and strategies that inhibit HSPA12A in cardiomyocytes might be a potential therapeutic intervention.

Oxidative stress in critically ill neonatal foals

BACKGROUND

Oxidative injury occurs in septic people, but the role of oxidative stress and antioxidants has rarely been evaluated in foals.

OBJECTIVES/HYPOTHESIS

To measure reactive oxygen species (ROS), biomarkers of oxidative injury, and antioxidants in neonatal foals. We hypothesized that ill foals would have higher blood concentrations of ROS and biomarkers of oxidative injury and lower concentrations of antioxidants compared to healthy foals.

ANIMALS

Seventy-two hospitalized and 21 healthy neonatal foals.

METHODS

Prospective cohort study. Reactive oxygen species (hydrogen peroxide [H2O2]), biomarkers of oxidative injury (malondialdehyde [MDA], protein carbonyl), and antioxidants (superoxide dismutase [SOD], catalase [CAT], glutathione, and glutathione reductase [GR] and peroxidase [GPx]) were measured from foals at admission. Measured variables were compared between healthy and ill foals using a 1-way ANOVA by Tukey's multiple comparisons test.

RESULTS

Ill foals (n = 51) had significantly higher mean concentrations of H2O2 (healthy 2.6 ± 1.4 nmol/mL, ill 6.8 ± 4.6 L nmol/mL; 95% CI), MDA (healthy 31.2 ± 14.4 nmol/mL, ill 114.3 ± 94.0 nmol/mL; 95% CI), and protein carbonyl (healthy 0.07 ± 0.01 nmol/mg protein, ill 0.12 ± 0.02 nmol/mg protein, 95% CI). Significant lower CAT (healthy 0.4 ± 0.3 mU/mg protein, ill 0.02 ± 0.02 mU/mg protein, 95% CI), glutathione (healthy 238.5 ± 101.9 μg/mL, ill 110.7 ± 37.8 μg/mL, 95% CI; P < .0001), GR (healthy 1.6 ± 1.8 mU/mg protein, ill 0.4 ± 0.5 mU/mg protein, 95% CI), and GPx (healthy 0.01 ± 0.003 mU/mg protein, ill 0.007 ± 0.002 mU/mg protein, 95% CI) were also noted.

CONCLUSIONS AND CLINICAL IMPORTANCE

Oxidative stress and lower antioxidant concentrations occur in ill and bacteremic neonatal foals. These variables should be considered during the treatment of ill foals.

Clostridium butyricum attenuates LPS-induced myocardial injury in septic mice by modulating CD4 + CD25 + FOXP3 + Treg

Sepsis-induced myocardial injury has become a major threat to patient health and safety. Intestinal microbiota imbalance plays a crucial role in sepsis regulation. Using 16srRNA technology, we explored how intestinal colonization of Clostridium butyricum over 28 days impacted mice with LPS-induced sepsis. Significant changes were noted in the gut microbiota of the mice, highlighting that C. butyricum can positively influence the immune state in septic myocardial injury models. The bacterium's ability to prevent intestinal mucosal damage and alleviate the immunosuppressive state during the later stages of sepsis by regulating CD4 + CD25 + FOXP3 + Treg cells is particularly noteworthy. This suggests a therapeutic role for C. butyricum in sepsis management by protecting against myocardial injury and improving immune regulation.

Desuccinylation of TBK1 by SIRT5 regulates inflammatory response of macrophages in sepsis

Tank-binding kinase 1 (TBK1) is a critical signal transducer in the nuclear factor κB (NF-κB) and interferon regulatory factor (IRF) pathways, essential for innate immunity. However, its negative regulation mechanisms remain unclear. This study demonstrates that TBK1 succinylation, regulated by desuccinylase SIRT5, inhibits lipopolysaccharide (LPS)/Toll-like receptor 4 (TLR4)-mediated NF-κB and IRF signaling activation. We identified three key succinylation sites on TBK1: K38, K154, and K692. In endotoxemia and sepsis models, reduced SIRT5 levels in macrophages increased TBK1 succinylation, inhibiting its binding to IRF3 and TRAF2 and suppressing the inflammatory response. In vivo, adoptive transfer of macrophages expressing the succinylation-resistant TBK1-2KR (K154/692R) mutant reversed the inflammatory cytokine suppression caused by SIRT5 deficiency, exacerbating sepsis-induced lung injury. These findings reveal a novel mechanism by which SIRT5 modulates TBK1 activity and macrophage-mediated inflammation during sepsis.

Diagnostic and prognostic value of disulfidptosis-related genes in sepsis

Background

Sepsis is a disease associated with high morbidity and mortality rates, especially among the elderly and patients in intensive care units. Disulfidptosis, a newly identified form of cell death triggered by disulfide stress, is emerging as a significant factor in disease progression. This study aimed to explore the diagnostic and prognostic value of disulfidptosis-related genes in sepsis.

Methods

We obtained two datasets from the Gene Expression Omnibus (GEO) database to conduct our analysis. Functional enrichment analysis was performed to identify relevant biological pathways. A protein-protein interaction network was constructed to identify hub genes critical to sepsis. Additionally, we analyzed the immune infiltration status in sepsis patients. The diagnostic value of these hub genes for sepsis was evaluated using nomograms, receiver operating characteristic (ROC) curves, and calibration curves in both training and validation datasets. Finally, a miRNA-immune-related hub genes (miRNA-IHGs) regulatory network was developed to elucidate the synergistic interactions between miRNAs and their target genes.

Results

A total of 3,469 differentially expressed genes (DEGs) were identified, of which seven were related to disulfidptosis (DR-DEGs). Functional enrichment analysis showed that DR-DEGs were significantly enriched in pathways related to actin dynamics. Five hub genes (MYH10, ACTN4, MYH9, FLNA, and IQGAP1) were identified as central to these processes. The analysis of immune infiltration revealed significantly lower levels of 11 immune cell types, while macrophages and regulatory T cells were significantly elevated in sepsis patients. The area under the ROC curves (AUCs) of the IHGs risk prediction model were 0.917 and 0.894 for the training and validation sets, respectively. A miRNA-IHGs regulatory network, comprising 17 nodes and 27 edges, was constructed, with MYH9 being the most frequently regulated by miRNAs.

Conclusion

The pathophysiological process of sepsis appears to involve disulfidptosis, highlighting it as a potential new therapeutic targets for sepsis management.

Ubiquitination in pyroptosis pathway: A potential therapeutic target for sepsis

Sepsis remains a significant clinical challenge, causing numerous deaths annually and representing a major global health burden. Pyroptosis, a unique form of programmed cell death characterized by cell lysis and the release of inflammatory mediators, is a crucial factor in the pathogenesis and progression of sepsis, septic shock, and organ dysfunction. Ubiquitination, a key post-translational modification influencing protein fate, has emerged as a promising target for managing various inflammatory conditions, including sepsis. This review integrates the current knowledge on sepsis, pyroptosis, and the ubiquitin system, focusing on the molecular mechanisms of ubiquitination within pyroptotic pathways activated during sepsis. By exploring how modulating ubiquitination can regulate pyroptosis and its associated inflammatory signaling pathways, this review provides insights into potential therapeutic strategies for sepsis, highlighting the need for further research into these complex molecular networks.

Disruption of the C5a/C5aR1 axis confers protection against hookworm infection in lung

Hookworms are soil-transmitted parasitic nematodes that penetrate the host skin before migrating to the lungs. With an estimated 500-700 million people infected worldwide, hookworm infections are a neglected tropical disease and a significant cause of morbidity, particularly in children, pregnant women, and immunocompromised individuals. Although there is ample evidence that complement activation is pivotal to elicit a protective host immune response against invasive pathogens, its role in hookworm infection remains insufficiently explored. Here, we investigated the complement anaphylatoxin, C5a, during the early lung stage of infection with Nippostrongylus brasiliensis in C57BL/6J wild type and C5aR1-/- mice. Despite the previously reported ability of lung larvae to evade complement activation, C5a was detectable locally in lung tissue and bronchoalveolar lavages. Surprisingly, C5aR1 presence directly contributed to the pathogenicity of hookworm infection. The burden of viable parasites in the lungs was mitigated in C5aR1-/- mice, compared to C57BL/6J mice 48 hours post-infection. Additionally, C5aR1-/- mice showed significantly reduced lung injury, lower cytokine release, attenuated alveolar hemorrhage, and limited alveolar-capillary barrier disruption. Neutrophils were the most abundant and highest C5aR1-expressing cell type in the alveolar space after infection. Deficiency of C5aR1 reduced the influx of neutrophils, monocytes, and eosinophils to the pulmonary airways. RNA sequencing of alveolar neutrophils revealed C5aR1-dependent regulation of the novel nuclear protein, DEDD2. In conclusion, our findings highlight the impact of C5aR1 signaling in neutrophils during hookworm infection uncovering an unexpected downside of complement activation in parasitic infection.

Non-invasive vagus nerve stimulation in anti-inflammatory therapy: mechanistic insights and future perspectives

Non-invasive vagus nerve stimulation (VNS) represents a transformative approach for managing a broad spectrum of inflammatory and autoimmune conditions, including rheumatoid arthritis and inflammatory bowel disease. This comprehensive review delineates the mechanisms underlying VNS, emphasizing the cholinergic anti-inflammatory pathway, and explores interactions within the neuro-immune and vagus-gut axes based on both clinical outcomes and pre-clinical models. Clinical applications have confirmed the efficacy of VNS in managing specific autoimmune diseases, such as rheumatoid arthritis, and chronic inflammatory conditions like inflammatory bowel disease, showcasing the variability in stimulation parameters and patient responses. Concurrently, pre-clinical studies have provided insights into the potential of VNS in modulating cardiovascular and broader inflammatory responses, paving the way for its translational application in clinical settings. Innovations in non-invasive VNS technology and precision neuromodulation are enhancing its therapeutic potential, making it a viable option for patients who are unresponsive to conventional treatments. Nonetheless, the widespread adoption of this promising therapy is impeded by regulatory challenges, patient compliance issues, and the need for extensive studies on long-term efficacy and safety. Future research directions will focus on refining VNS technology, optimizing treatment parameters, and exploring synergistic effects with other therapeutic modalities, which could revolutionize the management of chronic inflammatory and autoimmune disorders.

Radiation-induced eCIRP impairs macrophage bacterial phagocytosis

Macrophages are essential immune cells for host defense against bacterial pathogens after radiation injury. However, the role of macrophage phagocytosis in infection following radiation injury remains poorly examined. Extracellular cold-inducible RNA-binding protein is a damage-associated molecular pattern that dysregulates host immune system responses such as phagocytosis. We hypothesized that radiation-induced extracellular cold-inducible RNA-binding protein release impairs macrophage phagocytosis of bacteria. Adult healthy mice were exposed to 6.5 Gy total body irradiation. Primary peritoneal macrophages isolated from adult healthy mice were exposed to 6.5 Gy radiation. Extracellular cold-inducible RNA-binding protein-neutralizing monoclonal antibody was added to the cell culture prior to irradiation. Bacterial phagocytosis by peritoneal macrophages was assessed using pHrodo Green-labeled Escherichia coli 7 d after irradiation ex vivo and in vitro. Bacterial phagocytosis was also assessed after treatment with recombinant murine cold-inducible RNA-binding protein. Rac1 and ARP2 protein expression in cell lysates and extracellular cold-inducible RNA-binding protein levels in the peritoneal lavage were assessed by western blotting. Bacterial phagocytosis by peritoneal macrophages was significantly decreased after irradiation compared with controls ex vivo and in vitro. Rac1 and ARP2 expression in the peritoneal macrophages were downregulated after total body irradiation. Total body irradiation significantly increased extracellular cold-inducible RNA-binding protein levels in the peritoneal cavity. Recombinant murine cold-inducible RNA-binding protein significantly decreased bacterial phagocytosis in a dose-dependent manner. Extracellular cold-inducible RNA-binding protein monoclonal antibody restored bacterial phagocytosis by peritoneal macrophages after irradiation. Ionizing radiation exposure impairs bacterial phagocytosis by macrophages after irradiation. Neutralization of extracellular cold-inducible RNA-binding protein restores the phagocytic ability of macrophages after irradiation. Our findings elucidate a novel mechanism of immune dysfunction and provide a potential new therapeutic approach for limiting infection after radiation injury.

Predicting High-Flow Nasal Cannula Oxygen Therapy Failure in Patients With Acute Hypoxaemic Respiratory Failure Using Machine Learning: Model Development and External Validation

AIMS AND OBJECTIVES

To develop and validate a prediction model for high-flow nasal cannula (HFNC) failure in patients with acute hypoxaemic respiratory failure (AHRF).

BACKGROUND

AHRF accounts for a major proportion of intensive care unit (ICU) admissions and is associated with high mortality. HFNC is a non-invasive respiratory support technique that can improve patient oxygenation. However, HFNC failure, defined as the need for escalation to invasive mechanical ventilation, can lead to delayed intubation, prolonged mechanical ventilation and increased risk of mortality. Timely and accurate prediction of HFNC failure has important clinical implications. Machine learning (ML) can improve clinical prediction.

DESIGN

Multicentre observational study.

METHODS

This study analysed 581 patients from an academic medical centre in Boston and 180 patients from Guangzhou, China treated with HFNC for AHRF. The Boston dataset was randomly divided into a training set (90%, n = 522) and an internal validation set (10%, n = 59), and the model was externally validated using the Guangzhou dataset (n = 180). A random forest (RF)-based feature selection method was used to identify predictive factors. Nine machine learning algorithms were selected to build the predictive model. The area under the receiver operating characteristic curve (AUC) and performance evaluation parameters were used to evaluate the models.

RESULTS

The final model included 38 features selected using the RF method, with additional input from clinical specialists. Models based on ensemble learning outperformed other models (internal validation AUC: 0.83; external validation AUC: 0.75). Important predictors of HFNC failure include Glasgow Coma Scale scores and Sequential Organ Failure Assessment scores, albumin levels measured during HFNC treatment, ROX index at ICU admission and sepsis.

CONCLUSIONS

This study developed an interpretable ML model that accurately predicts the risk of HFNC failure in patients with AHRF.

RELEVANCE TO CLINICAL PRACTICE

Clinicians and nurses can use ML models for early risk assessment and decision support in AHRF patients receiving HFNC.

REPORTING METHOD

TRIPOD checklist for prediction model studies was followed in this study.

PATIENT OR PUBLIC CONTRIBUTION

Patients were involved in the sample of the study.

LncRNA-mRNA co-expression analysis reveals aquaporin-9-promoted neutrophil extracellular trap formation and inflammatory activation in sepsis

Sepsis is a life-threatening condition caused by an excessive inflammatory response to an infection. However, the precise regulatory mechanism of sepsis remains unclear. Using a strand-specific RNA-sequencing, we identified 115 hub differentially expressed long noncoding RNAs (lncRNAs) and 443 mRNAs in septic patients, primarily participated in crucial pathways including neutrophil extracellular trap (NET) formation and toll-like receptor signaling. Notably, NETs related gene aquaporin-9 (AQP9) and its associated lncRNAs exhibited significant upregulation in septic neutrophils. Functional experiments revealed AQP9 interacts with its lncRNAs to augment the formation of neutrophil NETs. In murine sepsis models, AQP9 inhibition with phloretin reduced proinflammatory cytokine production and lung damage. These findings provide crucial insights into the regulatory role of AQP9 in sepsis, unraveling its interaction with associated lncRNAs in transmitting downstream signals, holding promise in informing the development of novel therapeutic strategies aimed at ameliorating the debilitating effects of sepsis.

A short duration of mechanical ventilation alters redox status in the diaphragm and aggravates inflammation in septic mice

BACKGROUND

Mechanical ventilation (MV) is a life support method used to treat patients with respiratory failure. High tidal volumes during MV can cause ventilator-induced lung injury (VILI), but also affect other organs, such as the diaphragm (Dia) causing ventilator-induced diaphragmatic dysfunction (VIDD). VIDD is often associated with a complicated course on MV. Sepsis can induce inflammation and oxidative stress, contributing to the impairment of the Dia and worsening of the prognosis. This study evaluated the additive or synergistic effects of a short course of mechanical ventilation on Dia in healthy and septic adult mice.

METHODS

32 adult male C57BL/6 mice were randomly into four groups: Control (CG), non-ventilated animals instilled with saline solution (PBS1x); Lipopolysaccharide (LPS), non-ventilated animals instilled with PBS solution containing lipopolysaccharide; Mechanical Ventilation (MV) for 1 h, ventilated animals instilled with PBS solution; and Mechanical Ventilation and LPS (MV+LPS), ventilated animals instilled with PBS solution containing LPS. At the end of the experimental protocol, the animals were euthanized, then blood and diaphragm tissue samples were collected.

RESULTS

Evaluation of leukocyte/blood parameters and diaphragm muscle showed that MV, LPS and the combination of both were able to increase neutrophil count, creatine kinase, inflammatory mediators and oxidative stress in all groups compared to the control. MV and sepsis combined had additive effects on inflammation and lipid peroxidation.

CONCLUSIONS

A short course of Mechanical ventilation promotes inflammation and oxidative stress and, its combination with sepsis further increases local and systemic inflammation.

Biomimetic Nanomodulator Regulates Oxidative and Inflammatory Stresses to Treat Sepsis-Associated Encephalopathy

Sepsis-associated encephalopathy (SAE) is a devastating complication of sepsis, affecting approximately 70% of patients with sepsis in intensive care units (ICU). Although the pathophysiological mechanisms remain elusive, sepsis is typically accompanied by systemic inflammatory response syndrome (SIRS) and hyper-oxidative conditions. Here, we introduce a biomimetic nanomodulator (mAOI NP) that specifically targets inflammation site and simultaneously regulates oxidative and inflammatory stresses. mAOI NPs are constructed using metal-coordinated polyphenolic antioxidants (tannic acid) and flavonoid quercetin, which are then coated with macrophage membrane to enhance pharmacokinetics and enable SAE targeting. In a cecal ligation and puncture (CLP)-induced severe sepsis model, mAOI NPs effectively mitigate oxidative stress by purging reactive oxygen species, repairing mitochondrial damage and activating the Nrf2/HO-1 signaling pathway; while polarizing M1 macrophages or microglia toward anti-inflammatory M2 subtype. mAOI NPs potently inhibit sepsis progress, prolong overall survival from 25 to 66% and enhance learning and memory capabilities in SAE mice. Further proteomics analysis reveals that mAOI NPs modulate neurodevelopment processes related to learning and memory formation while also exerting anti-inflammatory and antioxidative effects on brain tissue responses associated with SAE pathology. This study offers significant potential for improving patient outcomes and revolutionizing the treatment landscape for this devastating complication of sepsis.

Heterozygous Apex1 deficiency exacerbates lipopolysaccharide-induced systemic inflammation in a murine model

The biological role of apurinic/apyrimidinic endonuclease 1/redox factor-1 (Apex1) in modulating systemic inflammation remains unclear. This study aimed to assess the impact of Apex1 deficiency on systemic inflammation triggered by lipopolysaccharide (LPS) in a murine model. The methods involved transcriptomic analysis and assessments of inflammatory responses in age-matched 8-week-old Apex1+/- and wild-type Apex1+/+ mice, generated using the CRISPR/Cas9 system. Apex1+/- mice displayed no overt changes in body weight, however, Apex1 protein expressions in tissues were significantly reduced compared to wild-type mice. Furthermore, in Apex1+/- mice transcriptomic analysis showed that genes associated with antioxidant pathways were downregulated, and levels of superoxide production, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and malondialdehyde (MDA) were increased. Moreover, hematological analysis showed increased neutrophil levels and a twofold increase in the count of splenic lymphocyte antigen 6 family member G+ (Ly6G+) neutrophils in the Apex1+/- mice compared to those in Apex1+/+ mice. Furthermore, following LPS treatment, the levels of cytokines and chemokines, including interleukin-1β, interleukin-10, tumor necrosis factor-α, and monocyte chemoattractant protein 1, increased in the Apex1+/- mice. The Kaplan-Meier curve showed a significant reduction in the survival rates of Apex1+/- mice treated with LPS compared to those of Apex1+/+ mice. The hepatic and lung injury scores and Ly6G+ neutrophil infiltration levels also increased in Apex1+/- mice after LPS treatment. These results showed that Apex1 deficiency exacerbated the LPS-induced tissue damage in the lung and liver. These findings illustrate that in vivo Apex1 deficiency exacerbates LPS-induced systemic inflammation, tissue damage, and mortality in a murine model, highlighting the crucial role of Apex1 in mitigating inflammatory responses and maintaining a holistic physiological equilibrium.

Circulating inflammatory cytokines and the risk of sepsis: a bidirectional mendelian randomization analysis

BACKGROUND

Sepsis is a life-threatening condition that is characterized by multiorgan dysfunction and caused by dysregulated cytokine networks, which are closely associated with sepsis progression and outcomes. However, currently available treatment strategies that target cytokines have failed. Thus, this study aimed to investigate the interplay between genetically predicted circulating concentrations of cytokines and the outcomes of sepsis and to identify potential targets for sepsis treatment.

METHODS

Data related to 35 circulating cytokines in 31,112 individuals (including 11,643 patients with sepsis) were included in genome-wide association studies (GWASs) from the UK Biobank and FinnGen consortia. A bidirectional two-sample Mendelian randomization (MR) analysis was performed using single nucleotide polymorphisms (SNPs) to evaluate the causal effects of circulating cytokines on sepsis outcomes and other cytokines.

RESULTS

A total of 35 inflammatory cytokine genes were identified in the GWASs, and 11 cytokines, including Interleukin-1 receptor antagonist (IL-1ra), macrophage inflammatory protein 1 (MIP1α), IL-16, et al., were associated with sepsis outcome pairs according to the selection criteria of the cis-pQTL instrument. Multiple MR methods verified that genetically predicted high circulating levels of IL-1ra or MIP1α were negatively correlated with genetic susceptibility to risk of sepsis, including sepsis (28-day mortality), septicaemia, streptococcal and pneumonia-derived septicaemia (P ≤ 0.01). Furthermore, genetic susceptibility of sepsis outcomes except sepsis (28-day mortality) markedly associated with the circulating levels of five cytokines, including active plasminogen activator inhibitor (PAI), interleukin 7 (IL-7), tumour necrosis factor alpha (TNF-α), beta nerve growth factor (NGF-β), hepatic growth factor (HGF) (P < 0.05). Finally, we observed that the causal interaction network between MIP1α or IL-1ra and other cytokines (P < 0.05).

CONCLUSIONS

This comprehensive MR analysis provides insights into the potential causal mechanisms that link key cytokines, particularly MIP1α, with risk of sepsis, and the findings suggest that targeting MIP1α may be a potential strategy for preventing sepsis.

Enhancing acute inflammatory and sepsis treatment: superiority of membrane receptor blockade

Conditions such as acute pancreatitis, ulcerative colitis, delayed graft function and infections caused by a variety of microorganisms, including gram-positive and gram-negative organisms, increase the risk of sepsis and therefore mortality. Immune dysfunction is a characterization of sepsis, so timely and effective treatment strategies are needed. The conventional approaches, such as antibiotic-based treatments, face challenges such as antibiotic resistance, and cytokine-based treatments have shown limited efficacy. To address these limitations, a novel approach focusing on membrane receptors, the initiators of the inflammatory cascade, is proposed. Membrane receptors such as Toll-like receptors, interleukin-1 receptor, endothelial protein C receptor, μ-opioid receptor, triggering receptor expressed on myeloid cells 1, and G-protein coupled receptors play pivotal roles in the inflammatory response, offering opportunities for rapid regulation. Various membrane receptor blockade strategies have demonstrated efficacy in both preclinical and clinical studies. These membrane receptor blockades act as early stage inflammation modulators, providing faster responses compared to conventional therapies. Importantly, these blockers exhibit immunomodulatory capabilities without inducing complete immunosuppression. Finally, this review underscores the critical need for early intervention in acute inflammatory and infectious diseases, particularly those posing a risk of progressing to sepsis. And, exploring membrane receptor blockade as an adjunctive treatment for acute inflammatory and infectious diseases presents a promising avenue. These novel approaches, when combined with antibiotics, have the potential to enhance patient outcomes, particularly in conditions prone to sepsis, while minimizing risks associated with antibiotic resistance and immune suppression.

SKLB023 protects against inflammation and apoptosis in sepsis-associated acute kidney injury via the inhibition of toll-like receptor 4 signaling

Sepsis-associated acute kidney injury (SA-AKI) is one of common critical illnesses with high morbidity and mortality. At present, effective therapeutic drugs for SA-AKI are remain lacking. SKLB023 is a synthetic small-molecule compound which exerts potent anti-inflammatory effects in our previous studies. Here, this study aimed to characterize the protective effect of SKLB023 on SA-AKI and explore its underlying mechanism. The SA-AKI experimental models have been established by cecum ligation/puncture (CLP) and lipopolysaccharide (LPS) injection in male C57BL/6J mice. SKLB023 was administered by gavage (50 or 25 mg/kg in CLP model and 50 mg/kg in LPS model) daily 3 days in advance and 30 min earlier on the day of modeling. Our results confirmed SKLB023 treatment could improve the survival of SA-AKI mice and ameliorate renal pathological injury, inflammation, and apoptosis in the two types of septic AKI mice. Mechanically, SKLB023 deceased the expression of TLR4 in LPS-triggered renal tubular epithelial cells, and inhibited the activation of downstream pathways including NF-κB and MAPK pathways. Our study suggested that SKLB023 is expected to be a potential drug for the prevention and treatment of septic AKI.

Association between the red cell distribution width and mortality in elderly patients with non-traumatic coma: An observational cohort study

Elevated red blood cell distribution width (RDW) can be associated with disease severity. However, studies on RDW for the prognosis of elderly patients with non-traumatic coma (NTC) are lacking. This study aims to examine the relationship between RDW and outcomes in elderly patients with NTC. This observational cohort study included elderly patients (aged ≥ 65 years) with NTC between January 2022 and December 2022. We measured RDW upon patient arrival at the emergency department (ED). We conducted a multivariable analysis using logistic regression of relevant covariates to predict in-hospital mortality. Survival curves based on 30-day mortality were designed using the Kaplan-Meier method. The primary outcome was in-hospital mortality, and the secondary outcome was 30-day mortality. A total of 689 patients were included in the study, and in-hospital mortality was 29.6% (n = 204). Our results found that the RDWs of non-survivors were significantly greater than those of survivors (14.6% vs 13.6%). Multivariable analysis showed that RDWs at ED arrival were independently associated with in-hospital mortality (odds ratio, 1.126; 95% confidence interval, 1.047-1.212; P < .001). The Kaplan-Meier curve indicated that the survival probability of patients with a low RDW was greater than those with a high RDW. Having a high RDW at ED arrival was associated with in-hospital mortality in elderly patients with NTC.

Modulation of anti-cardiac fibrosis immune responses by changing M2 macrophages into M1 macrophages

BACKGROUND

Macrophages play a crucial role in the development of cardiac fibrosis (CF). Although our previous studies have shown that glycogen metabolism plays an important role in macrophage inflammatory phenotype, the role and mechanism of modifying macrophage phenotype by regulating glycogen metabolism and thereby improving CF have not been reported.

METHODS

Here, we took glycogen synthetase kinase 3β (GSK3β) as the target and used its inhibitor NaW to enhance macrophage glycogen metabolism, transform M2 phenotype into anti-fibrotic M1 phenotype, inhibit fibroblast activation into myofibroblasts, and ultimately achieve the purpose of CF treatment.

RESULTS

NaW increases the pH of macrophage lysosome through transmembrane protein 175 (TMEM175) and caused the release of Ca2+ through the lysosomal Ca2+ channel mucolipin-2 (Mcoln2). At the same time, the released Ca2+ activates TFEB, which promotes glucose uptake by M2 and further enhances glycogen metabolism. NaW transforms the M2 phenotype into the anti-fibrotic M1 phenotype, inhibits fibroblasts from activating myofibroblasts, and ultimately achieves the purpose of treating CF.

CONCLUSION

Our data indicate the possibility of modifying macrophage phenotype by regulating macrophage glycogen metabolism, suggesting a potential macrophage-based immunotherapy against CF.

Myricanol attenuates sepsis-induced inflammatory responses by nuclear factor erythroid 2-related factor 2 signaling and nuclear factor kappa B/mitogen-activated protein kinase pathway via upregulating Sirtuin 1

Sepsis, a life-threatening condition characterized by dysregulated immune responses, remains a significant clinical challenge. Myricanol, a natural compound, plays a variety of roles in regulating lipid metabolism, anti-cancer, anti-neurodegeneration, and it could act as an Sirtuin 1 (SIRT1) activator. This study aimed to explore the therapeutic potential and underlying mechanism of myricanol in the lipopolysaccharide (LPS)-induced sepsis model. In vivo studies revealed that myricanol administration significantly improved the survival rate of LPS-treated mice, effectively mitigating LPS-induced inflammatory responses in lung tissue. Furthermore, in vitro studies demonstrated that myricanol treatment inhibited the expression of pro-inflammatory cytokines, attenuated signal pathway activation, and reduced oxidative stress in macrophages. In addition, we demonstrated that myricanol selectively enhances SIRT1 activation in LPS-stimulated macrophages, and all of the protective effect of myricanol were reversed through SIRT1 silencing. Remarkably, the beneficial effects of myricanol against LPS-induced sepsis were abolished in SIRT1 myeloid-specific knockout mice, underpinning the critical role of SIRT1 in mediating myricanol's therapeutic efficacy. In summary, this study provides significant evidence that myricanol acts as a potent SIRT1 activator, targeting inflammatory signal pathways and oxidative stress to suppress excessive inflammatory responses. Our findings highlight the potential of myricanol as a novel therapeutic agent for the treatment of LPS-induced sepsis.

Predicting the potentially exacerbation of severe viral pneumonia in hospital by MuLBSTA score joint CD4 + and CD8 +T cell counts: construction and verification of risk warning model

PURPOSE

This study mainly focuses on the immune function and introduces CD4+, CD8+ T cells and their ratios based on the MuLBSTA score, a previous viral pneumonia mortality risk warning model, to construct an early warning model of severe viral pneumonia risk.

METHODS

A retrospective single-center observational study was operated from January 2021 to December 2022 at the People's Hospital of Liangjiang New Area, Chongqing, China. A total of 138 patients who met the criteria for viral pneumonia in hospital were selected and their data, including demographic data, comorbidities, laboratory results, CT scans, immunologic and pathogenic tests, treatment regimens, and clinical outcomes, were collected and statistically analyzed.

RESULTS

Forty-one patients (29.7%) developed severe or critical illness. A viral pneumonia severe risk warning model was successfully constructed, including eight parameters: age, bacterial coinfection, CD4+, CD4+/CD8+, multiple lung lobe infiltrations, smoking, hypertension, and hospital admission days. The risk score for severe illness in patients was set at 600 points. The model had good predictive performance (AUROC = 0.94397), better than the original MuLBSTA score (AUROC = 0.8241).

CONCLUSION

A warning system constructed based on immune function has a good warning effect on the risk of severe conversion in patients with viral pneumonia.

Immunotherapy in the context of sepsis-induced immunological dysregulation

Sepsis is a clinical syndrome caused by uncontrollable immune dysregulation triggered by pathogen infection, characterized by high incidence, mortality rates, and disease burden. Current treatments primarily focus on symptomatic relief, lacking specific therapeutic interventions. The core mechanism of sepsis is believed to be an imbalance in the host's immune response, characterized by early excessive inflammation followed by late immune suppression, triggered by pathogen invasion. This suggests that we can develop immunotherapeutic treatment strategies by targeting and modulating the components and immunological functions of the host's innate and adaptive immune systems. Therefore, this paper reviews the mechanisms of immune dysregulation in sepsis and, based on this foundation, discusses the current state of immunotherapy applications in sepsis animal models and clinical trials.

Recent Advances in IRAK1: Pharmacological and Therapeutic Aspects

Interleukin receptor-associated kinase (IRAK) proteins are pivotal in interleukin-1 and Toll-like receptor-mediated signaling pathways. They play essential roles in innate immunity and inflammation. This review analyzes and discusses the physiological functions of IRAK1 and its associated diseases. IRAK1 is involved in a wide range of diseases such as dry eye, which highlights its potential as a therapeutic target under various conditions. Various IRAK1 inhibitors, including Pacritinib and Rosoxacin, show therapeutic potential against malignancies and inflammatory diseases. The covalent IRAK1 inhibitor JH-X-119-01 shows promise in B-cell lymphomas, emphasizing the significance of covalent bonds in its activity. Additionally, the emergence of selective IRAK1 degraders, such as JNJ-101, provides a novel strategy by targeting the scaffolding function of IRAK1. Thus, the evolving landscape of IRAK1-targeted approaches provides promising avenues for increasingly safe and effective therapeutic interventions for various diseases.

Effects of Crude Extract of Glycyrrhiza Radix and Atractylodes macrocephala on Immune and Antioxidant Capacity of SPF White Leghorn Chickens in an Oxidative Stress Model

The natural edible characteristics of Chinese herbs have led more and more people to study them as an alternative product to antibiotics. In this study, crude extracts of Glycyrrhiza radix and Atractylodes macrocephala (abbreviated as GRAM) with glycyrrhizic acid content not less than 0.2 mg/g were selected to evaluate the effects of GRAM on the immune and antioxidant capacity of model animals. Thirty 21-day-old male Leghorn chickens were weighed and randomly assigned to one of three groups of ten animals each. The treatments comprised a control group (CON), in which saline was injected at day 31, day 33, and day 35, an LPS-treated group (LPS), in which LPS (0.5 mg/kg of BW) was injected at day 31, day 33, and day 35, and finally a GRAM and LPS-treated group, (G-L) in which a GRAM-treated diet (at GRAM 2 g/kg) was fed from day 21 to day 35 with LPS injection (0.5 mg/kg of BW) at day 31, day 33, and day 35. The results of diarrhea grade and serum antioxidant measurement showed that the LPS group had obvious diarrhea symptoms, serum ROS and MDA were significantly increased, and T-AOC was significantly decreased. The oxidative stress model of LPS was successfully established. The results of immune and antioxidant indexes showed that feeding GRAM significantly decreased levels of the pro-inflammatory factors TNF-α, IL-1β, and IL-6 (p < 0.05) and significantly increased levels of the anti-inflammatory factors IL-4 and IL-10 and levels of the antioxidant enzymes GSH-Px and CAT (p < 0.05). GRAM resisted the influence of LPS on ileum morphology, liver, and immune organs and maintained normal index values for ileum morphology, liver, and immune organs. In summary, this study confirmed the antidiarrheal effect of GRAM, which improved the immune and antioxidant capacity of model animals by regulating inflammatory cytokine levels and antioxidant enzyme activity in poultry.

Adjunctive immunotherapeutic agents in patients with sepsis and septic shock: a multidisciplinary consensus of 23

BACKGROUND

In the last decades, several adjunctive treatments have been proposed to reduce mortality in septic shock patients. Unfortunately, mortality due to sepsis and septic shock remains elevated and NO trials evaluating adjunctive therapies were able to demonstrate any clear benefit. In light of the lack of evidence and conflicting results from previous studies, in this multidisciplinary consensus, the authors considered the rational, recent investigations and potential clinical benefits of targeted adjunctive therapies.

METHODS

A panel of multidisciplinary experts defined clinical phenotypes, treatments and outcomes of greater interest in the field of adjunctive therapies for sepsis and septic shock. After an extensive systematic literature review, the appropriateness of each treatment for each clinical phenotype was determined using the modified RAND/UCLA appropriateness method.

RESULTS

The consensus identified two distinct clinical phenotypes: patients with overwhelming shock and patients with immune paralysis. Six different adjunctive treatments were considered the most frequently used and promising: (i) corticosteroids, (ii) blood purification, (iii) immunoglobulins, (iv) granulocyte/monocyte colony-stimulating factor and (v) specific immune therapy (i.e. interferon-gamma, IL7 and AntiPD1). Agreement was achieved in 70% of the 25 clinical questions.

CONCLUSIONS

Although clinical evidence is lacking, adjunctive therapies are often employed in the treatment of sepsis. To address this gap in knowledge, a panel of national experts has provided a structured consensus on the appropriate use of these treatments in clinical practice.

Establishment and assessment of mortality risk prediction model in patients with sepsis based on early-stage peripheral lymphocyte subsets

This study is aimed to explore the value of lymphocyte subsets in evaluating the severity and prognosis of sepsis. The counts of lymphocytes, CD3+ T cells, CD4+ T cells, CD8+ T cells, CD19+ B cells, and NK cells significantly decreased between day 1 and day 3 in both the survivor and the non-survivor groups. The peripheral lymphocyte subsets (PLS) at day 1 were not significantly different between the survivor and the non-survivor groups. However, at day 3, the counts of lymphocytes, CD3+ T cells, CD4+ T cells, and NK cells were remarkably lower in the non-survivor group. No significant differences in CD8+ T cells, or CD19+ B cells were observed. The PLS index was independently and significantly associated with the 28-day mortality risk in septic patients (OR: 3.08, 95% CI: 1.18-9.67). Based on these clinical parameters and the PLS index, we developed a nomograph for evaluating the individual mortality risk in sepsis. The area under the curve of prediction with the PLS index was significantly higher than that from the model with only clinical parameters (0.912 vs. 0.817). Our study suggests that the decline of PLS occurred in the early stage of sepsis. The new novel PLS index can be an independent predictor of 28-day mortality in septic patients. The prediction model based on clinical parameters and the PLS index has relatively high predicting ability.

A novel therapeutic approach to modulate the inflammatory cascade: A timely exogenous local inflammatory response attenuates the sepsis-induced cytokine storm

BACKGROUND

The emergence of severe sepsis is contingent upon the occurrence of a cytokine storm (CS), a multifaceted process intricately entwined with the temporal dimension, thereby rendering the infection response remarkably intricate. Consequently, it becomes imperative to discern and accurately identify the optimal timing for interventions, predicated upon the dynamic timeline of inflammatory changes. Moreover, the administration of exogenous low-dose pro-inflammatory agents has exhibited the potential to impede the relentless progression of the inflammatory cascade. Hence, the present study aims to scrutinize the impact of exogenous Local Inflammatory Response (eLIR) on the body surface in the context of the inflammatory cascade during sepsis, within a temporal framework, with a particular emphasis on the point of exacerbation of inflammation.

METHODS

Rats were induced sterile sepsis by intraperitoneal injection of zymosan (ZY) at an appropriate dosage. The temporal progression of inflammatory changes and eLIR effects were described based on the trend of serum crucial inflammatory cytokines, tring to quest time-point of inflammatory aggravation in sepsis. Then, the varying degrees of surface inflammation caused by eLIR on this time point leading to the final effects on the inflammatory cascade response were explored. In addition, given the authentic pathological progression of sepsis, further observation was conducted on the impact of another intervention timing of eLIR on the inflammatory cascade. The survival rate was measured. Serum and organ related inflammatory cytokines were detected, and organ histopathology was investigated.

RESULTS

In present study, a dosage of 600 mg/kg ZY was found to be optimal for the sterile sepsis model. Initiating eLIR 6 h prior to ZY injection, the maximum effect point of eLIR could be precisely align with the inflammatory aggravation point of sterile sepsis. Initiating eLIR at this time, 3 sessions of eLIR were found to be more effective than 1 or 2 sessions in mitigating inflammatory responses during the initial stage of inflammation and the peak of inflammation. Notably, the findings also suggested that this intervention improve survival rate. In addition, the anti-inflammatory efficacy has been substantially diminished by the prompt initiation of 3 sessions of eLIR immediately after ZY injection at the onset of sepsis. Similarly, the current findings did not demonstrate a statistically significant enhancement in survival rates with eLIR at this time point.

CONCLUSIONS

Compared with the initial stage of inflammation, low-scale inflammation caused by a certain intensity of eLIR (3 sessions) on the body surface can more effectively pry the inflammation aggravation time-point, thereby shifting the pro-inflammatory to anti-inflammatory milieu, impeding the disproportionate cytokines release in inflammatory diseases, slowing down the inflammatory cascade, and improving the survival rate of sepsis.

Hematopoiesis Revolves Around the Primordial Evolutional Rhythm of Purinergic Signaling and Innate Immunity - A Journey to the Developmental Roots

A cell's most significant existential task is to survive by ensuring proper metabolism, avoiding harmful stimuli, and adapting to changing environments. It explains why early evolutionary primordial signals and pathways remained active and regulate cell and tissue integrity. This requires energy supply and a balanced redox state. To meet these requirements, the universal intracellular energy transporter purine nucleotide-adenosine triphosphate (ATP) became an important signaling molecule and precursor of purinergic signaling after being released into extracellular space. Similarly, ancient proteins involved in intracellular metabolism gave rise to the third protein component (C3) of the complement cascade (ComC), a soluble arm of innate immunity. These pathways induce cytosol reactive oxygen (ROS) and reactive nitrogen species (RNS) that regulate the redox state of the cells. While low levels of ROS and RNS promote cell growth and differentiation, supra-physiological concentrations can lead to cell damage by pyroptosis. This balance explains the impact of purinergic signaling and innate immunity on cell metabolism, organogenesis, and tissue development. Subsequently, along with evolution, new regulatory cues emerge in the form of growth factors, cytokines, chemokines, and bioactive lipids. However, their expression is still modulated by both primordial signaling pathways. This review will focus on the data that purinergic signaling and innate immunity carry on their ancient developmental task in hematopoiesis and specification of hematopoietic stem/progenitor cells (HSPCs). Moreover, recent evidence shows both these regulatory pathways operate in a paracrine manner and inside HSPCs at the autocrine level.

Peroxiredoxin 3 has a crucial role in the macrophage polarization by regulating mitochondrial homeostasis

Acute lung injury (ALI) is one of the life-threatening complications of sepsis, and macrophage polarization plays a crucial role in the sepsis-associated ALI. However, the regulatory mechanisms of macrophage polarization in ALI and in the development of inflammation are largely unknown. In this study, we demonstrated that macrophage polarization occurs in sepsis-associated ALI and is accompanied by mitochondrial dysfunction and inflammation, and a decrease of PRDX3 promotes the initiation of macrophage polarization and mitochondrial dysfunction. Mechanistically, PRDX3 overexpression promotes M1 macrophages to differentiate into M2 macrophages, and enhances mitochondrial functional recovery after injury by reducing the level of glycolysis and increasing TCA cycle activity. In conclusion, we identified PRDX3 as a critical hub integrating oxidative stress, inflammation, and metabolic reprogramming in macrophage polarization. The findings illustrate an adaptive mechanism underlying the link between macrophage polarization and sepsis-associated ALI.

Oxidative Stress in Sepsis: A Focus on Cardiac Pathology

This study aims to analyze post-mortem human cardiac specimens, to verify and evaluate the existence or extent of oxidative stress in subjects whose cause of death has been traced to sepsis, through immunohistological oxidative/nitrosative stress markers. Indeed, in the present study, i-NOS, NOX2, and nitrotyrosine markers were higher expressed in the septic death group when compared to the control group, associated with also a significant increase in 8-OHdG, highlighting the pivotal role of oxidative stress in septic etiopathogenesis. In particular, 70% of cardiomyocyte nuclei from septic death specimens showed positivity for 8-OHdG. Furthermore, intense and massive NOX2-positive myocyte immunoreaction was noticed in the septic group, as nitrotyrosine immunostaining intense reaction was found in the cardiac cells. These results demonstrated a correlation between oxidative and nitrosative stress imbalance and the pathophysiology of cardiac dysfunction documented in cases of sepsis. Therefore, subsequent studies will focus on the expression of oxidative stress markers in other organs and tissues, as well as on the involvement of the intracellular pattern of apoptosis, to better clarify the complex pathogenesis of multi-organ failure, leading to support the rationale for including therapies targeting redox abnormalities in the management of septic patients.

Costunolide attenuates LPS-induced inflammation and lung injury through inhibiting IKK/NF-κB signaling

Inflammation is an important pathological process of many acute and chronic diseases, such as sepsis, arthritis, and cancer. Many factors can lead to an inflammatory state of the body, among which bacterial infection plays an important role. Bacterial infection often leads to sepsis, acute lung injury (ALI), or its more serious form of acute respiratory distress syndrome, which are the main fatal diseases in intensive care units. Costunolide has been reported to possess excellent anti-inflammatory activity; however, whether it can affect inflammation induced by gram-negative bacterial is still unclear. Lipopolysaccharide (LPS) stimulated mouse peritoneal macrophages (MPMs) to release proinflammatory cytokines was used as the cell model. The mouse model of sepsis and ALI was built through injecting intravenously and intratracheally of LPS. In the present study, costunolide inhibited LPS-induced inflammatory response through IKK/NF-κB signaling pathway in macrophages. In vivo, costunolide attenuated LPS-induced septic death in mice. Meanwhile, costunolide treatment alleviated LPS-induced lung injury and inflammation via inhibiting the infiltration of inflammatory cells and the expression of inflammatory cytokines. Taken together, these results demonstrated that costunolide could attenuate gram-negative bacterial induced inflammation and diseases and might be a potential candidate for the treatment of inflammatory diseases.

Carrimycin ameliorates lipopolysaccharide and cecal ligation and puncture-induced sepsis in mice

Carrimycin (CA), sanctioned by China's National Medical Products Administration (NMPA) in 2019 for treating acute bronchitis and sinusitis, has recently been observed to exhibit multifaceted biological activities, encompassing anti-inflammatory, antiviral, and anti-tumor properties. Despite these applications, its efficacy in sepsis treatment remains unexplored. This study introduces a novel function of CA, demonstrating its capacity to mitigate sepsis induced by lipopolysaccharide (LPS) and cecal ligation and puncture (CLP) in mice models. Our research employed in vitro assays, real-time quantitative polymerase chain reaction (RT-qPCR), and RNA-seq analysis to establish that CA significantly reduces the levels of pro-inflammatory cytokines, namely tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6), in response to LPS stimulation. Additionally, Western blotting and immunofluorescence assays revealed that CA impedes Nuclear Factor Kappa B (NF-κB) activation in LPS-stimulated RAW264.7 cells. Complementing these findings, in vivo experiments demonstrated that CA effectively alleviates LPS- and CLP-triggered organ inflammation in C57BL/6 mice. Further insights were gained through 16S sequencing, highlighting CA's pivotal role in enhancing gut microbiota diversity and modulating metabolic pathways, particularly by augmenting the production of short-chain fatty acids in mice subjected to CLP. Notably, a comparative analysis revealed that CA's anti-inflammatory efficacy surpasses that of equivalent doses of aspirin (ASP) and TIENAM. Collectively, these findings suggest that CA exhibits significant therapeutic potential in sepsis treatment. This discovery provides a foundational theoretical basis for the clinical application of CA in sepsis management.

Effect of neutrophil to lymphocyte ratio on prognosis of elderly patients with severe sepsis combined with diabetes mellitus

BACKGROUND

To investigate the predictive value of neutrophil-to-lymphocyte ratio (NLR) in the short-term prognosis of elderly patients with severe sepsis combined with diabetes mellitus (DM).

METHODS

The clinical data of 162 elderly patients with severe sepsis combined with DM from January 2018 to December 2022 were retrospectively collected. These patients were divided into a survival group (n = 104) and a death group (n = 58) according to 90-day prognosis. The number of neutrophils, lymphocytes, and NLR were compared. The optimal cut-off value for NLR to predict 90-day prognosis in elderly patients with severe sepsis combined with DM was determined using Receiver Operator Characteristic (ROC) curves, and the patients were divided into high and low NLR groups depending on the optimal cut-off value. The Kaplan-Meier method was used to plot the survival curves of the high and low NLR groups. Risk factors for the 90-day death in elderly patients with severe sepsis combined with DM were analyzed by a multivariate cox regression model.

RESULTS

There were no significant differences in gender, age, history of hypertension and hyperlipidemia, intensive care unit (ICU) stay, duration of mechanical ventilation, and oxygenation index between the survival group and death group (p > 0.05). However, acute physiological and chronic health evaluation II (APACHE II) scores, and sepsis-related organ failure assessment (SOFA) scores were significantly lower in the survival group compared with the death group (p < 0.05). In the survival group, neutrophils counts and NLR were much lower than those in the death group, while lymphocytes counts were much higher (p < 0.05). ROC curves showed that the optimal cut-off value for NLR to predict 90-day mortality in elderly patients with severe sepsis combined with DM was 3.482. Patients were divided into high NLR and low NLR groups based on whether NLR was ≥ 3.482. In terms of the log-rank test results, patients in the low NLR group had a significantly higher 90-day survival rate than those in the high NLR group (Logrank χ2 = 8.635, p = 0.003). The multivariate cox regression model showed that the length of ICU stay longer than 15 days and NLR ≥ 3.482 were independent risk factors for 90-day prognosis in elderly patients with severe sepsis combined with DM.

CONCLUSION

NLR ≥ 3.482 can be used to predict whether poor prognosis occurs in the short term after illness in elderly patients with severe sepsis combined with DM, and has good assessment value.

Systemic inflammatory response syndrome triggered by blood-borne pathogens induces prolonged dendritic cell paralysis and immunosuppression

Blood-borne pathogens can cause systemic inflammatory response syndrome (SIRS) followed by protracted, potentially lethal immunosuppression. The mechanisms responsible for impaired immunity post-SIRS remain unclear. We show that SIRS triggered by pathogen mimics or malaria infection leads to functional paralysis of conventional dendritic cells (cDCs). Paralysis affects several generations of cDCs and impairs immunity for 3-4 weeks. Paralyzed cDCs display distinct transcriptomic and phenotypic signatures and show impaired capacity to capture and present antigens in vivo. They also display altered cytokine production patterns upon stimulation. The paralysis program is not initiated in the bone marrow but during final cDC differentiation in peripheral tissues under the influence of local secondary signals that persist after resolution of SIRS. Vaccination with monoclonal antibodies that target cDC receptors or blockade of transforming growth factor β partially overcomes paralysis and immunosuppression. This work provides insights into the mechanisms of paralysis and describes strategies to restore immunocompetence post-SIRS.

NMI Functions as Immuno-regulatory Molecule in Sepsis by Regulating Multiple Signaling Pathways

Sepsis-induced tissue and organ damage is caused by an overactive inflammatory response, immune dysfunction, and coagulation dysfunction. Danger-associated molecular pattern (DAMP) molecules play a critical role in the excessive inflammation observed in sepsis. In our previous research, we identified NMI as a new type of DAMP molecule that promotes inflammation in sepsis by binding to toll-like receptor 4 (TLR4) on macrophage surfaces, activating the NF-κB pathway, and releasing pro-inflammatory cytokines. However, it is still unknown whether NMI plays a significant role in other pathways. Our analysis of bulk and single-cell transcriptome data from the GEO database revealed a significant increase in NMI expression in neutrophils and monocytes in sepsis patients. It is likely that NMI functions through multiple receptors in sepsis, including IFNAR1, IFNAR2, TNFR1, TLR3, TLR1, IL9R, IL10RB, and TLR4. Furthermore, the correlation between NMI expression and the activation of NF-κB, MAPK, and JAK pathways, as well as the up-regulation of their downstream pro-inflammatory factors, demonstrates that NMI may exacerbate the inflammatory response through these signaling pathways. Finally, we demonstrated that STAT1 phosphorylation was enhanced in RAW cells upon stimulation with NMI, supporting the activation of JAK signaling pathway by NMI. Collectively, these findings shed new light on the functional mechanism of NMI in sepsis.