The immune system's role in sepsis progression, resolution, and long-term outcome

Central angiotensin-(1-7) attenuates hypoglycemia in sepsis-like conditions via reducing systemic and hepatic inflammation

Sepsis is understood as the result of initiating systemic inflammation derived from an inadequate host response against pathogens. In its acute phase, sepsis is marked by an exacerbated reaction to infection, tissue damage, organ failure, and metabolic dysfunction. Among these, hypoglycemia, characterized by disorders of the gluconeogenesis pathway, is related to one of the leading causes of mortality in septic patients. Recent research has investigated the involvement of sympathetic efferent neuroimmune pathways during systemic inflammation. These pathways can be stimulated by several centrally administered drugs, including Angiotensin-(1-7) (Ang-(1-7)). Therefore, the present study aims to evaluate the effects of central treatment with Ang-(1-7) on hypoglycemia during endotoxemia. For this, male Wistar Hannover rats underwent stereotaxic surgery for intracerebroventricular (i.c.v.) administration of Ang-(1-7) and cannulation of the jugular vein for lipopolysaccharide (LPS) injection. Our results demonstrate that LPS was capable of inducing hypoglycemia and that prior central treatment with Ang-(1-7) attenuated this effect. Our data also show that Ang-(1-7) reduced plasma concentrations of TNF-α, IL-1β, IL-6, and nitric oxide, in addition to the decrease and increase of hepatic IL-6 and IL-10 respectively, in animals subjected to systemic inflammation by LPS, resulting in the reduction of systemic and hepatic inflammation, thus attenuating the deleterious effects of LPS on phosphoenolpyruvate carboxykinase protein content. In summary, the data suggest that central treatment with Ang-(1-7) attenuates hypoglycemia induced by endotoxemia, probably through anti-inflammatory action, leading to reestablishing hepatic gluconeogenesis.

Immunologic effect and clinical impact of erythromycin in septic patients: A randomized clinical trial

To investigate the potential regulatory effect of erythromycin added to standard care in septic patients on sepsis biomarkers and clinical outcome. It was a single-blind randomized trial including critical septic patients. The primary endpoint was the change in the TNF/IL-10 ratio between days 0 and 6. Changes in other biomarkers, vasopressor use, and 28-day mortality were secondary endpoints. One hundred and ten patients were examined (erythromycin group, n = 55 versus placebo group, n = 55). Clinical features of the groups were well matched. Erythromycin addition had no beneficial effects on the TNF/IL-10 ratio or mortality (51% vs. 47%, p = 0.62). Both groups' serum TNF/IL-10 ratios did not significantly rise (from 0.48 [0.34-1.18] to 0.59 [0.21-1.10] vs. 0.65 [0.25-1.14] to 0.93 [0.24-1.88] in the erythromycin and placebo groups, respectively; p values = 0.86 and 0.12). Serum Procalcitonin (PCT) and CRP dropped considerably in the Erythromycin group, whereas only PCT showed a drop in the placebo group. On day 6, the non-survivors' serum TNF/IL-10 ratio was lower than that of the survivors (0.55 [0.17-1.04] vs 1.08 [0.4-2.28], p = 0.029). Neither the pro/anti-inflammatory imbalance nor the mortality were impacted by the addition of erythromycin to standard care in septic patients (ClinicalTrials.gov ID: NCT04665089 (11/12/2020)).

Inhibition of PI3K p110δ rebalanced Th17/Treg and reduced macrophages pyroptosis in LPS-induced sepsis

Sepsis is a systemic inflammatory response syndrome caused by trauma or infection, which can lead to multiple organ dysfunction. In severe cases, sepsis can also progress to septic shock and even death. Effective treatments for sepsis are still under development. This study aimed to determine if targeting the PI3K/Akt signaling with CAL-101, a PI3K p110δ inhibitor, could alleviate lipopolysaccharide (LPS)-induced sepsis and contribute to immune tolerance. Our findings indicated that CAL-101 treatment improved survival rates and alleviated the progression of LPS-induced sepsis. Compared to antibiotics, CAL-101 not only restored the Th17/regulatory T cells (Treg) balance but also enhanced Treg cell function. Additionally, CAL-101 promoted type 2 macrophage (M2) polarization, inhibited TNF-α secretion, and increased IL-10 secretion. Moreover, CAL-101 treatment reduced pyroptosis in peritoneal macrophages by inhibiting caspase-1/gasdermin D (GSDMD) activation. This study provides a mechanistic basis for future clinical exploration of targeted therapeutics and immunomodulatory strategies in the treatment of sepsis.

The concomitant use of ultra short beta-blockers with vasopressors and inotropes in critically ill patients with septic shock: A systematic review and meta-analysis of randomized controlled trials

Background

Septic shock is associated with systemic inflammatory response, hemodynamic instability, impaired sympathetic control, and the development of multiorgan dysfunction that requires vasopressor or inotropic support. The regulation of immune function in sepsis is complex and varies over time. However, activating Beta-2 receptors and blocking Beta-1 receptors reduces the proinflammatory response by influencing cytokine production. Evidence that supports the concomitant use of ultra short beta-blockers with inotropes and vasopressors in patients with septic shock is still limited. This study aimed to evaluate the use of ultra short beta-blockers and its impact on the ICU related outcomes such as mortality, length of stay, heart rate control, shock resolution, and vasopressors/inotropes requirements.

Methods

A systematic review and meta-analysis of randomized controlled trials including critically ill patients with septic shock who received inotropes and vasopressors. Patients who received either epinephrine or norepinephrine without beta-blockers "control group" were compared to patients who received ultra short beta-blockers concomitantly with either epinephrine or norepinephrine "Intervention group". MEDLINE and Embase databases were utilized to systematically search for studies investigating the use of ultra short beta-blockers in critically ill patients on either epinephrine or norepinephrine from inception to October 10, 2023. The primary outcome was the 28-day mortality. While, length of stay, heart rate control, and inotropes/ vasopressors requirements were considered secondary outcomes.

Results

Among 47 potentially relevant studies, nine were included in the analysis. The 28-day mortality risk was lower in patients with septic shock who used ultra short beta-blockers concomitantly with either epinephrine or norepinephrine compared with the control group (RR (95%CI): 0.69 (0.53, 0.89), I2=26%; P=0.24). In addition, heart rate was statistically significantly lower with a standardized mean difference (SMD) of -22.39 (95% CI: -24.71, -20.06) among the beta-blockers group than the control group. The SMD for hospital length of stay and the inotropes requirement were not statistically different between the two groups (SMD (95%CI): -0.57 (-2.77, 1.64), and SMD (95%CI): 0.08 (-0.02, 0.19), respectively).

Conclusion

The use of ultra short beta-blockers concomitantly with either epinephrine or norepinephrine in critically ill patients with septic shock was associated with better heart rate control and survival benefits without increment in the inotropes and vasopressors requirement.

Verapamil and tangeretin enhances the M1 macrophages to M2 type in lipopolysaccharide-treated mice and inhibits the P-glycoprotein expression by downregulating STAT1/STAT3 and upregulating SOCS3

LPS induced sepsis is a complex process involving various immune cells and signaling molecules. Dysregulation of macrophage polarization and ROS production contributed to the pathogenesis of sepsis. PGP is a transmembrane transporter responsible for the efflux of a number of drugs and also expressed in murine macrophages. Natural products have been shown to decrease inflammation and expression of efflux transporters. However, no treatment is currently available to treat LPS induced sepsis. Verapamil and Tangeretin also reported to attenuate lipopolysaccharide-induced inflammation. However, the effects of verapamil or tangeretin on lipopolysaccharide (LPS)-induced sepsis and its detailed anti-inflammatory mechanism have not been reported. Here, we have determined that verapamil and tangeretin protects against LPS-induced sepsis by suppressing M1 macrophages populations and also through the inhibition of P-glycoprotein expression via downregulating STAT1/STAT3 and upregulating SOCS3 expression in macrophages. An hour before LPS (10 mg/kg) was administered; mice were given intraperitoneal injections of either verapamil (5 mg/kg) or tangeretin (5 mg/kg). The peritoneal macrophages from different experimental groups of mice were isolated. Hepatic, pulmonary and splenic morphometric analyses revealed that verapamil and tangeretin decreased the infiltration of neutrophils into the tissues. Verapamil and tangeritin also enhanced the activity of SOD, CAT, GRX and GSH level in all the tissues tested. verapamil or tangeretin pre-treated mice shifted M1 macrophages to M2 type possibly through the inhibition of P-glycoprotein expression via downregulating STAT1/STAT3 and upregulating SOCS3 expression. Hence, both these drugs have shown protective effects in sepsis via suppressing iNOS, COX-2, oxidative stress and NF-κB signaling in macrophages. Therefore, in our study we can summarize that mice were treated with either Vera or Tan before LPS administration cause an elevated IL-10 by the macrophages which enhances the SOCS3 expression, and thereby able to limits STAT1/STAT3 inter-conversion in the macrophages. As a result, NF-κB activity is also getting down regulated and ultimately mitigating the adverse effect of inflammation caused by LPS in resident macrophages. Whether verapamil or tangeretin offers such protection possibly through the inhibition of P-glycoprotein expression in macrophages needs clarification with the bio availability of these drugs under PGP inhibited conditions is a limitation of this study.

EFHD2 regulates T cell receptor signaling and modulates T helper cell activation in early sepsis

EFHD2 (EF-hand domain family, member D2) has been identified as a calcium-binding protein with immunomodulatory effects. In this study, we characterized the phenotype of Efhd2-deficient mice in sepsis and examined the biological functions of EFHD2 in peripheral T cell activation and T helper (Th) cell differentiation. Increased levels of EFHD2 expression accompanied peripheral CD4+ T cell activation in the early stages of sepsis. Transcriptomic analysis indicated that immune response activation was impaired in Efhd2-deficient CD4+ T cells. Further, Efhd2-deficient CD4+ T cells isolated from the spleen of septic mice showed impaired T cell receptor (TCR)-induced Th differentiation, especially Th1 and Th17 differentiation. In vitro data also showed that Efhd2-deficient CD4+ T cells exhibit impaired Th1 and Th17 differentiation. In the CD4+ T cells and macrophages co-culture model for antigen presentation, the deficiency of Efhd2 in CD4+ T cells resulted in impaired formation of immunological synapses. In addition, Efhd2-deficient CD4+ T cells exhibited reduced levels of phospho-LCK and phospho-ZAP70, and downstream transcription factors including Nfat, Nfκb and Nur77 following TCR engagement. In summary, EFHD2 may promote TCR-mediated T cell activation subsequent Th1 and Th17 differentiation in the early stages of sepsis by regulating the intensity of TCR complex formation.

Dysregulated dendritic cells in sepsis: functional impairment and regulated cell death

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Studies have indicated that immune dysfunction plays a central role in the pathogenesis of sepsis. Dendritic cells (DCs) play a crucial role in the emergence of immune dysfunction in sepsis. The major manifestations of DCs in the septic state are abnormal functions and depletion in numbers, which are linked to higher mortality and vulnerability to secondary infections in sepsis. Apoptosis is the most widely studied pathway of number reduction in DCs. In the past few years, there has been a surge in studies focusing on regulated cell death (RCD). This emerging field encompasses various forms of cell death, such as necroptosis, pyroptosis, ferroptosis, and autophagy-dependent cell death (ADCD). Regulation of DC's RCD can serve as a possible therapeutic focus for the treatment of sepsis. Throughout time, numerous tactics have been devised and effectively implemented to improve abnormal immune response during sepsis progression, including modifying the functions of DCs and inhibiting DC cell death. In this review, we provide an overview of the functional impairment and RCD of DCs in septic states. Also, we highlight recent advances in targeting DCs to regulate host immune response following septic challenge.

Sepsis as a Potential Risk Factor for Upper Gastrointestinal Bleeding in Critically Ill Patients: A Systematic Review and Meta-analysis

Purpose: Sepsis is a common and critical condition in intensive care units (ICUs) known to complicate patient outcomes. Previous studies have indicated an association between sepsis and various ICU morbidities, including upper gastrointestinal bleeding (UGIB). However, the extent of this relationship and its implications in ICU settings remain inadequately quantified. This study aims to elucidate the association between sepsis and the risk of UGIB in ICU patients. Methods: A comprehensive meta-analysis was conducted, encompassing nine studies with a total of nearly 9000 participants. These studies reported events for both sepsis and nonsepsis patients separately. Pooled odds ratios (ORs) were calculated to assess the risk of UGIB in septic versus nonseptic ICU patients. Subgroup analyses were conducted based on age and study design, and both unadjusted and adjusted ORs were examined. Results: The pooled OR indicated a significant association between sepsis and UGIB (OR = 3.276, 95% CI: 1.931 to 5.557). Moderate heterogeneity was observed (I² = 43.9%). The association was significant in adults (pooled OR = 4.083) but not in children. No difference in association was found based on the study design. Unadjusted and adjusted ORs differed slightly, indicating the influence of confounding factors. Conclusion: This meta-analysis reveals a significant association between sepsis and an increased risk of UGIB in ICU patients, particularly in adults. These findings highlight the need for vigilant monitoring and proactive management of septic ICU patients to mitigate the risk of UGIB. Future research should focus on understanding the underlying mechanisms and developing tailored preventive strategies.

The molecular landscape of sepsis severity in infants: enhanced coagulation, innate immunity, and T cell repression

Introduction

Sepsis remains a major cause of mortality and morbidity in infants. In recent years, several gene marker strategies for the early identification of sepsis have been proposed but only a few have been independently validated for adult cohorts and applicability to infant sepsis remains unclear. Biomarkers to assess disease severity and risks of shock also represent an important unmet need.

Methods

To elucidate characteristics driving sepsis in infants, we assembled a multi-transcriptomic dataset from public microarray datasets originating from five independent studies pertaining to bacterial sepsis in infant < 6-months of age (total n=335). We utilized a COmbat co-normalization strategy to enable comparative evaluation across multiple studies while preserving the relationship between cases and controls.

Results

We found good concordance with only two out of seven of the published adult sepsis gene signatures (accuracy > 80%), highlighting the narrow utility of adult-derived signatures for infant diagnosis. Pseudotime analysis of individual subjects' gene expression profiles showed a continuum of molecular changes forming tight clusters concurrent with disease progression between healthy controls and septic shock cases. In depth gene expression analyses between bacteremia, septic shock, and healthy controls characterized lymphocyte activity, hemostatic processes, and heightened innate immunity during the molecular transition toward a state of shock.

Discussion

Our analysis revealed the presence of multiple significant transcriptomic perturbations that occur during the progression to septic shock in infants that are characterized by late-stage induction of clotting factors, in parallel with a heightened innate immune response and a suppression of adaptive cell functionality.

An improved mouse model of sepsis based on intraperitoneal injections of the enriched culture of cecum slurry

AIM

Sepsis is a life-threatening clinical syndrome comprising multiorgan dysfunctions caused by a disproportionate body immune response. There are several animal sepsis models which are based on cecum ligation, cecal puncture, and cecum slurry injection. The major limitation of all current sepsis models is the high variability owing to the variable degree of ligation, puncture and inconsistent microbial composition used for sepsis initiation. The primary objective of this work is to demonstrate the feasibility of a standardized method for sepsis development.

MATERIALS AND METHODS

The cecal slurry bacterial culture was developed and preserved in glycerol stocks. Antibiotics aztreonam and vancomycin were used for generating several defined, enriched cecal slurry bacterial cultures. Mice survival was assessed until 48 hrs post injection, and the tissue samples were collected after 10 hrs from sepsis initiation.

KEY FINDINGS

The results indicate that increasing polymicrobial load resulted in lower survival rates and was associated with the higher number of infiltrating immune cells and necrosis. H&E (haematoxylin & eosin) staining & serum markers revealed that septic mice exhibited increased inflammation and significant damage to the liver and kidneys. The defined Gram-negative and Gram-positive specific cecal slurry bacterial cultures were developed and their efficiency in inducing sepsis was characterized.

SIGNIFICANCE

Enriched cecal slurry bacterial cultures can be stored in glycerol stocks at -80 °C. This has an ethical advantage of avoiding unnecessary animal euthanasia for each experiment and provides a standardization capability of sepsis development.

Bacterial heat shock protein: A new crosstalk between T lymphocyte and macrophage via JAK2/STAT1 pathway in bloodstream infection

Bloodstream infection (BSI) refers to the infection of blood by pathogens. Severe immune response to BSI can lead to sepsis, a systemic infection leading to multiple organ dysfunction, coupled with drug resistance, mortality, and limited clinical treatment options. This work aims to further investigate the new interplay between bacterial exocrine regulatory protein and host immune cells in the context of highly drug-resistant malignant BSI. Whether interfering with related regulatory signaling pathways can reverse the inflammatory disorder of immune cells. In-depth analysis of single-cell sequencing results in Septic patients for potential immunodeficiency factors. Analysis of key proteins enriched by host cells and key pathways using proteomics. Cell models and animal models validate the pathological effects of DnaK on T cells, MAITs, macrophages, and osteoclasts. The blood of patients was analyzed for the immunosuppression of T cells and MAITs. We identified that S. maltophilia-DnaK was enriched in immunodeficient T cells. The activation of the JAK2/STAT1 axis initiated the exhaustion of T cells. Septic patients with Gram-negative bacterial infections exhibited deficiencies in MAITs, which correspond to IFN-γ. Cellular and animal experiments confirmed that DnaK could facilitate MAIT depletion and M1 polarization of macrophages. Additionally, Fludarabine mitigated M1 polarization of blood, liver, and spleen in mice. Interestingly, DnaK also repressed osteoclastogenesis of macrophages stimulated by RANKL. S.maltophilia-DnaK prompts the activation of the JAK2/STAT1 axis in T cells and the M1 polarization of macrophages. Targeting the DnaK's crosstalk can be a potentially effective approach for treating the inflammatory disorder in the broad-spectrum drug-resistant BSI.

The effects of antioxidant supplementation on short-term mortality in sepsis patients

Background

The occurrence and development of sepsis are related to the excessive production of oxygen free radicals and the weakened natural clearance mechanism. Further dependable evidence is required to clarify the effectiveness of antioxidant therapy, especially its impact on short-term mortality.

Objectives

The purpose of this systematic review and meta-analysis was to evaluate the effect of common antioxidant therapy on short-term mortality in patients with sepsis.

Methods

According to PRISMA guidelines, a systematic literature search on antioxidants in adults sepsis patients was performed on PubMed/Medline, Embase, and the Cochrane Library from the establishment of the database to November 2023. Antioxidant supplements can be a single-drug or multi-drug combination: HAT (hydrocortisone, ascorbic acid, and thiamine), ascorbic acid, thiamine, N-acetylcysteine and selenium. The primary outcome was the effect of antioxidant treatment on short-term mortality, which included 28-day mortality, in-hospital mortality, intensive care unit mortality, and 30-day mortality. Subgroup analyses of short-term mortality were used to reduce statistical heterogeneity and publication bias.

Results

Sixty studies of 130,986 sepsis patients fulfilled the predefined criteria and were quantified and meta-analyzed. Antioxidant therapy reduces the risk of short-term death in sepsis patients by multivariate meta-analysis of current data, including a reduction of in-hospital mortality (OR = 0.81, 95% CI 0.67 to 0.99; P = 0.040) and 28-day mortality (OR = 0.81, 95% CI 0.69 to 0.95]; P = 0.008). Particularly in subgroup analyses, ascorbic acid treatment can reduce in-hospital mortality (OR = 0.66, 95% CI 0.90 to 0.98; P = 0.006) and 28-day mortality (OR = 0.43, 95% CI 0.24 to 0.75; P = 0.003). However, the meta-analysis of RCTs found that antioxidant therapy drugs, especially ascorbic acid, did substantially reduce short-term mortality(OR = 0.78, 95% CI 0.62 to 0.98; P = 0.030; OR = 0.57, 95% CI 0.36 to 0.91; P = 0.020).

Conclusions

According to current data of RCTs, antioxidant therapy, especially ascorbic acid, has a trend of improving short-term mortality in patients with sepsis, but the evidence remains to be further demonstrated.

The Concomitant Occurrence of Hidradenitis Suppurativa and Fournier's Gangrene

Background

Fournier's gangrene represents a life-threatening necrotising infection affecting the perineal region, while hidradenitis suppurativa is characterised by a chronic inflammatory skin condition. The simultaneous occurrence of both conditions is exceedingly rare.

Case description

A 42-year-old female with a documented history of severe untreated hidradenitis suppurativa presented for shortness of breath, fever and lethargy, along with extensive wounds and skin breakdown involving the left axilla, perineum, lower back, lumbosacral region and bilateral gluteal areas, extending to the perineum. Upon presentation, the patient was in a state of septic shock, and a diagnosis of actively manifesting Fournier's gangrene was established at the site of the pre-existing hidradenitis suppurativa lesions. Despite the implementation of an aggressive multidisciplinary approach incorporating surgical interventions, antibiotic therapy and intensive care measures, the patient's condition deteriorated, culminating in septic shock, multi-organ failure and eventual demise. In this report, we discuss both clinical entities, their similarities and differences, and the possible mechanisms by which they may have co-occurred.

Conclusion

The co-existence of hidradenitis suppurativa and Fournier's gangrene poses unique challenges, given the rapid progression of Fournier's gangrene within the context of hidradenitis suppurativa, potentially suggesting the latter as a predisposing factor. This case underscores the importance of vigilant screening and management of hidradenitis suppurativa.

LEARNING POINTS

Clinicians should be aware of the potential association between hidradenitis suppurativa and Fournier's gangrene, especially in patients with shared risk factors.Both conditions present diagnostic and treatment challenges, emphasising the importance of a thorough differential diagnosis and a tailored selection of antibiotics.Proactive and continuous care is crucial in managing chronic diseases such as hidradenitis suppurativa to prevent severe complications, for example Fournier's gangrene.

Free Radical-Associated Gene Signature Predicts Survival in Sepsis Patients

Sepsis continues to overwhelm hospital systems with its high mortality rate and prevalence. A strategy to reduce the strain of sepsis on hospital systems is to develop a diagnostic/prognostic measure that identifies patients who are more susceptible to septic death. Current biomarkers fail to achieve this outcome, as they only have moderate diagnostic power and limited prognostic capabilities. Sepsis disrupts a multitude of pathways in many different organ systems, making the identification of a single powerful biomarker difficult to achieve. However, a common feature of many of these perturbed pathways is the increased generation of reactive oxygen species (ROS), which can alter gene expression, changes in which may precede the clinical manifestation of severe sepsis. Therefore, the aim of this study was to evaluate whether ROS-related circulating molecular signature can be used as a tool to predict sepsis survival. Here we created a ROS-related gene signature and used two Gene Expression Omnibus datasets from whole blood samples of septic patients to generate a 37-gene molecular signature that can predict survival of sepsis patients. Our results indicate that peripheral blood gene expression data can be used to predict the survival of sepsis patients by assessing the gene expression pattern of free radical-associated -related genes in patients, warranting further exploration.

Applications of peptides in nanosystems for diagnosing and managing bacterial sepsis

Sepsis represents a critical medical condition stemming from an imbalanced host immune response to infections, which is linked to a significant burden of disease. Despite substantial efforts in laboratory and clinical research, sepsis remains a prominent contributor to mortality worldwide. Nanotechnology presents innovative opportunities for the advancement of sepsis diagnosis and treatment. Due to their unique properties, including diversity, ease of synthesis, biocompatibility, high specificity, and excellent pharmacological efficacy, peptides hold great potential as part of nanotechnology approaches against sepsis. Herein, we present a comprehensive and up-to-date review of the applications of peptides in nanosystems for combating sepsis, with the potential to expedite diagnosis and enhance management outcomes. Firstly, sepsis pathophysiology, antisepsis drug targets, current modalities in management and diagnosis with their limitations, and the potential of peptides to advance the diagnosis and management of sepsis have been adequately addressed. The applications have been organized into diagnostic or managing applications, with the last one being further sub-organized into nano-delivered bioactive peptides with antimicrobial or anti-inflammatory activity, peptides as targeting moieties on the surface of nanosystems against sepsis, and peptides as nanocarriers for antisepsis agents. The studies have been grouped thematically and discussed, emphasizing the constructed nanosystem, physicochemical properties, and peptide-imparted enhancement in diagnostic and therapeutic efficacy. The strengths, limitations, and research gaps in each section have been elaborated. Finally, current challenges and potential future paths to enhance the use of peptides in nanosystems for combating sepsis have been deliberately spotlighted. This review reaffirms peptides' potential as promising biomaterials within nanotechnology strategies aimed at improving sepsis diagnosis and management.

L-AP Alleviates Liver Injury in Septic Mice by Inhibiting Macrophage Activation via Suppressing NF-κB and NLRP3 Inflammasome/Caspase-1 Signal Pathways

Liver injury and progressive liver failure are severe life-threatening complications in sepsis, further worsening the disease and leading to death. Macrophages and their mediated inflammatory cytokine storm are critical regulators in the occurrence and progression of liver injury in sepsis, for which effective treatments are still lacking. l-Ascorbic acid 6-palmitate (L-AP), a food additive, can inhibit neuroinflammation by modulating the phenotype of the microglia, but its pharmacological action in septic liver damage has not been fully explored. We aimed to investigate L-AP's antisepticemia action and the possible pharmacological mechanisms in attenuating septic liver damage by modulating macrophage function. We observed that L-AP treatment significantly increased survival in cecal ligation and puncture-induced WT mice and attenuated hepatic inflammatory injury, including the histopathology of the liver tissues, hepatocyte apoptosis, and the liver enzyme levels in plasma, which were comparable to NLRP3-deficiency in septic mice. L-AP supplementation significantly attenuated the excessive inflammatory response in hepatic tissues of septic mice in vivo and in cultured macrophages challenged by both LPS and ATP in vitro, by reducing the levels of NLRP3, pro-IL-1β, and pro-IL-18 mRNA expression, as well as the levels of proteins for p-I-κB-α, p-NF-κB-p65, NLRP3, cleaved-caspase-1, IL-1β, and IL-18. Additionally, it impaired the inflammasome ASC spot activation and reduced the inflammatory factor contents, including IL-1β and IL-18 in plasma/cultured superannuants. It also prevented the infiltration/migration of macrophages and their M1-like inflammatory polarization while improving their M2-like polarization. Overall, our findings revealed that L-AP protected against sepsis by reducing macrophage activation and inflammatory cytokine production by suppressing their activation in NF-κB and NLRP3 inflammasome signal pathways in septic liver.

A Secondary Retrospective Analysis of the Predictive Value of Neutrophil-Reactive Intensity (NEUT-RI) in Septic and Non-Septic Patients in Intensive Care

BACKGROUND

Effective identification and management in the early stages of sepsis are critical for achieving positive outcomes. In this context, neutrophil-reactive intensity (NEUT-RI) emerges as a promising and easily interpretable parameter. This study aimed to assess the predictive value of NEUT-RI in diagnosing sepsis and to evaluate its prognostic significance in distinguishing 28-day mortality outcomes.

MATERIALS

This study is a secondary, retrospective, observational analysis. Clinical data upon ICU admission were collected. We enrolled septic patients and a control group of critically ill patients without sepsis criteria. The patients were divided into subgroups based on renal function for biomarker evaluation with 28-day outcomes reported for septic and non-septic patients.

RESULTS

A total of 200 patients were included in this study. A significant difference between the "septic" and "non-septic" groups was detected in the NEUT-RI plasma concentration (53.80 [49.65-59.05] vs. 48.00 [46.00-49.90] FI, p < 0.001, respectively). NEUT-RI and procalcitonin (PCT) distinguished between not complicated sepsis and septic shock (PCT 1.71 [0.42-12.09] vs. 32.59 [8.83-100.00], <0.001 and NEUT-RI 51.50 [47.80-56.30] vs. 56.20 [52.30-61.92], p = 0.005). NEUT-RI, PCT, and CRP values were significantly different in patients with "renal failure". NEUT-RI and PCT at admission in the ICU in the septic group were higher in patients who died (58.80 [53.85-73.10] vs. 53.05 [48.90-57.22], p = 0.005 and 39.56 [17.39-83.72] vs. 3.22 [0.59-32.32], p = 0.002, respectively). Both NEUT-RI and PCT showed a high negative predictive value and low positive predictive value.

CONCLUSIONS

The inflammatory biomarkers assessed in this study offer valuable support in the early diagnosis of sepsis and could have a possible role in anticipating the outcome. NEUT-RI elevation appears particularly promising for early sepsis detection and severity discrimination upon admission.

Proteome characterization of liver-kidney comorbidity after microbial sepsis

Sepsis is a life-threatening condition that occurs when the body responds to an infection but subsequently triggers widespread inflammation and impaired blood flow. These pathologic responses can rapidly cause multiple organ dysfunction or failure either one by one or simultaneously. The fundamental common mechanisms involved in sepsis-induced multiple organ dysfunction remain unclear. Here, employing quantitative global and phosphoproteomics, we examine the liver's temporal proteome and phosphoproteome changes after moderate sepsis induced by cecum ligation and puncture. In total, 4593 global proteins and 1186 phosphoproteins according to 3275 phosphosites were identified. To characterize the liver-kidney comorbidity after sepsis, we developed a mathematical model and performed cross-analyses of liver and kidney proteome data obtained from the same set of mice. Beyond immune response, we showed the commonly disturbed pathways and key regulators of the liver-kidney comorbidity are linked to energy metabolism and consumption. Our data provide open resources to understand the communication between the liver and kidney as they work to fight infection and maintain homeostasis.

PAK1 Promotes Inflammation Induced by Sepsis through the Snail/CXCL2 Signaling Pathway

Sepsis is a severe syndrome characterized by organ dysfunction, resulting from a systemic imbalance in response to infection. PAK1 plays a critical role in various diseases. The present study aimed to explore and delineate the mechanism of PAK1 in inflammation induced by sepsis. Bioinformatics analysis was performed to assess PAK1, snail, and CXCL2 expression in the whole blood of septic patients and the pathways enriched with PAK1. To simulate the sepsis model, THP-1 cells were stimulated with lipopolysaccharide. Gene expression was evaluated using qRT-PCR, while cell viability was assessed using CCK-8 assay. Cell apoptosis was tested with flow cytometry. Expression of inflammatory factors in cells following different treatments was analyzed using the enzyme linked immunosorbent assay (ELISA). Dual-luciferase and chromatin immunoprecipitation assays were conducted to verify the binding relationship between PAK1 and the snail. Mouse models of cecal ligation and puncture were established, and hematoxylin and eosin staining and ELISA were employed to detect the infiltration levels of inflammatory cells and the expression of related protective factors in lung, liver, and kidney tissues. The results demonstrated upregulation of PAK1, snail, and CXCL2 in the whole blood of septic patients, with PAK1 being enriched in the chemokine-related pathway. Knockdown of PAK1 significantly promoted the apoptosis of LPS-stimulated THP-1 cells and inhibited the expression of inflammatory factors. PAK1 upregulated the expression of the snail, which in turn promoted the expression of CXCL2. Thus, PAK1 mediated the sepsis-induced inflammatory response through the snail/CXCL2 pathway. In conclusion, PAK1 played a role in promoting inflammation induced by sepsis through the snail/CXCL2 axis, thereby providing a potential therapeutic target for the management of sepsis.

Dose-Dependent Effects of Lipopolysaccharide on the Endothelium-Sepsis versus Metabolic Endotoxemia-Induced Cellular Senescence

The endothelium, the innermost cell layer of blood vessels, is not only a physical barrier between the bloodstream and the surrounding tissues but has also essential functions in vascular homeostasis. Therefore, it is not surprising that endothelial dysfunction is associated with most cardiovascular diseases. The functionality of the endothelium is compromised by endotoxemia, the presence of bacterial endotoxins in the bloodstream with the main endotoxin lipopolysaccharide (LPS). Therefore, this review will focus on the effects of LPS on the endothelium. Depending on the LPS concentration, the outcomes are either sepsis or, at lower concentrations, so-called low-dose or metabolic endotoxemia. Sepsis, a life-threatening condition evoked by hyperactivation of the immune response, includes breakdown of the endothelial barrier resulting in failure of multiple organs. A deeper understanding of the underlying mechanisms in the endothelium might help pave the way to new therapeutic options in sepsis treatment to prevent endothelial leakage and fatal septic shock. Low-dose endotoxemia or metabolic endotoxemia results in chronic inflammation leading to endothelial cell senescence, which entails endothelial dysfunction and thus plays a critical role in cardiovascular diseases. The identification of compounds counteracting senescence induction in endothelial cells might therefore help in delaying the onset or progression of age-related pathologies. Interestingly, two natural plant-derived substances, caffeine and curcumin, have shown potential in preventing endothelial cell senescence.

Bovine lactoferrin inhibits inflammatory response and apoptosis in lipopolysaccharide-induced acute lung injury by targeting the PPAR-γ pathway

BACKGROUND

Lactoferrin (LF) is an iron-binding multifunctional cationic glycoprotein. Previous studies have demonstrated that LF may be a potential drug for treating acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In this study, we explored the anti-inflammatory effect and mechanism of bovine lactoferrin (bLF) in ALI using the RNA sequencing (RNA-seq) technology and transcriptome analysis.

METHODS AND RESULTS

Based on the differentially expressed genes (DEGs) obtained from RNA-seq of the Lung from mouse model, the bioinformatics workflow was implemented using the BGISEQ-500 platform. The protein-protein interaction (PPI) network was obtained using STRING, and the hub gene was screened using Cytoscape. To verify the results of transcriptome analysis, the effects of bLF on Lipopolysaccharide (LPS)-induced BEAS-2B cells and its anti-reactive oxygen species (ROS), anti-inflammatory, and antiapoptotic effects were studied via Cell Counting Kit-8 (CCK-8) test, active oxygen detection test, ELISA, and western blot assay. Transcriptome analysis revealed that two hub gene modules of DEGs were screened via PPI analysis using the STRING and MCODE plug-ins of Cytoscape. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that these core modules are enriched in the PPAR (peroxisome proliferator-activated receptor) and AMPK (AMP-activated protein kinase) signaling pathways. Through cell experiments, our study shows that bLF can inhibit ROS, inflammatory reaction, and LPS-induced BEAS-2B cell apoptosis, which are significantly antagonized by the PPAR-γ inhibitor GW9662.

CONCLUSION

This study has suggested that the PPAR-γ pathway is the critical target of bLF in anti-inflammatory reactions and apoptosis of ALI, which provides a direction for further research.

Evaluating the efficacy of standardized pressure ulcer management protocols in the prevention of pressure injuries among patients undergoing neurosurgical procedures

Pressure injuries are a significant concern for patients undergoing neurosurgical procedures due to prolonged immobility and the complexity of care. This study evaluates the efficacy of standardized pressure ulcer management protocols in preventing pressure injuries and enhancing patient care in a neurosurgical context. A comprehensive retrospective analysis was conducted at a single institution from December 2020 to December 2023, comparing 50 patients who received standardized pressure ulcer management (intervention group) with 50 patients who received conventional care (control group). The study assessed the incidence of pressure ulcers, patient comfort levels using the Kolcaba Comfort Scale and sleep quality using the Richards-Campbell Sleep Questionnaire (RCSQ). Statistical analysis was performed using SPSS software, version 27.0, applying t-tests and chi-square tests as appropriate. The intervention group exhibited a significantly lower incidence of pressure ulcers at all measured time points post-surgery compared to the control group. Patient comfort levels in the intervention group were consistently higher across psychological, environmental, physiological and socio-cultural domains. Sleep quality metrics, including sleep depth, latency to sleep onset and overall sleep quality, were significantly improved in the intervention group. The implementation of standardized pressure ulcer management protocols in neurosurgical care significantly reduces the incidence of pressure injuries, enhances patient comfort and improves sleep quality. These findings highlight the importance of adopting structured care protocols to improve postoperative outcomes and patient well-being in neurosurgical settings.

Effector function and neutrophil cell death in the severity of sepsis with diabetes mellitus

Sepsis, a life-threatening condition resulting from immune dysregulation, is typically triggered by bacterial infections and commonly coexists with diabetes mellitus. Neutrophils are the first responders to infection and require regulated activation to control pathogen and damage-associated molecular patterns. Dysregulation of neutrophil activation leads to uncontrolled inflammatory responses, often observed in both sepsis and diabetes patients. Neutrophil dysregulation, characterized by effector dysfunction and inadequate cell death processes, can serve as a biomarker for assessing sepsis severity, particularly in diabetic patients. This review provides information on the relationship between effector function, neutrophil cell death, and the severity of sepsis in individuals with diabetes mellitus, aiming to shed light on the mechanisms underlying sepsis progression. Topics covered in the review include an overview of effector function of neutrophil cells, mechanisms of neutrophil cell death, and dysregulation of effectors and neutrophil cell death processes in sepsis severity with diabetes mellitus.

Lymphopenia is associated with broad host response aberrations in community-acquired pneumonia

OBJECTIVES

Lymphopenia at hospital admission occurs in over one-third of patients with community-acquired pneumonia (CAP), yet its clinical relevance and pathophysiological implications remain underexplored. We evaluated outcomes and immune features of patients with lymphopenic CAP (L-CAP), a previously described immunophenotype characterized by admission lymphocyte count <0.724 × 109 cells/L.

METHODS

Observational study in 149 patients admitted to a general ward for CAP. We measured 34 plasma biomarkers reflective of inflammation, endothelial cell responses, coagulation, and immune checkpoints. We characterized lymphocyte phenotypes in 29 patients using spectral flow cytometry.

RESULTS

L-CAP occurred in 45 patients (30.2%) and was associated with prolonged time-to-clinical-stability (median 5 versus 3 days), also when we accounted for competing events for reaching clinical stability and adjusted for baseline covariates (subdistribution hazard ratio 0.63; 95% confidence interval 0.45-0.88). L-CAP patients demonstrated a proportional depletion of CD4 T follicular helper cells, CD4 T effector memory cells, naïve CD8 T cells and IgG+ B cells. Plasma biomarker analyses indicated increased activation of the cytokine network and the vascular endothelium in L-CAP.

CONCLUSIONS

L-CAP patients have a protracted clinical recovery course and a more broadly dysregulated host response. These findings highlight the prognostic and pathophysiological relevance of admission lymphopenia in patients with CAP.

Dexmedetomidine suppressed the biological behavior of RAW264.7 cells treated with LPS by down-regulating HOTAIR

Background

Previous studies have revealed dexmedetomidine have potential protective effects on vital organs by inhibiting the release of inflammatory cytokines. To investigate the effects of dexmedetomidine on sepsis, especially in the initial inflammatory stage of sepsis. RAW264.7 cells were used as the cell model in this study to elucidate the underlying mechanisms.

Methods

In this study, we conducted several assays to investigate the mechanisms of dexmedetomidine and HOTAIR in sepsis. Cell viability was assessed using the CCK-8 kit, while inflammation responses were measured using ELISA for IL-1β, IL-6, and TNF-α. Additionally, we employed qPCR, MeRIP, and RIP to further explore the underlying mechanisms.

Results

Our findings indicate that dexmedetomidine treatment enhanced cell viability and reduced the production of inflammatory cytokines in LPS-treated RAW264.7 cells. Furthermore, we observed that the expression of HOTAIR was increased in LPS-treated RAW264.7 cells, which was then decreased upon dexmedetomidine pre-treatment. Further investigation demonstrated that HOTAIR could counteract the beneficial effects of dexmedetomidine on cell viability and cytokine production. Interestingly, we discovered that YTHDF1 targeted HOTAIR and was upregulated in LPS-treated RAW264.7 cells, but reduced in dexmedetomidine treatment. We also found that YTHDF1 increased HOTAIR and HOTAIR m6A levels.

Conclusions

Collectively, our results suggest that dexmedetomidine downregulates HOTAIR and YTHDF1 expression, which in turn inhibits the biological behavior of LPS-treated RAW264.7 cells. This finding has potential implications for the prevention and treatment of sepsis-induced kidney injury.

STING contributes to lipopolysaccharide-induced tubular cell inflammation and pyroptosis by activating endoplasmic reticulum stress in acute kidney injury

Recently, innate immunity and inflammation were recognized as the key factors for acute kidney injury (AKI) caused by sepsis, which is closely related to high mortality. Stimulator of interferon genes (STING) has emerged as a critical component of innate immune and inflammatory responses. However, the role of STING in the pathogenesis of septic AKI remains unclear. This study demonstrated that the STING was significantly activated in tubular cells induced by lipopolysaccharide (LPS) in vivo and in vitro. Tubule-specific STING knockout attenuated LPS-induced renal dysfunction and pathological changes. Mechanistically, the STING pathway promotes NOD-like receptor protein 3 (NLRP3) activation. STING triggers endoplasmic reticulum (ER) stress to induce mitochondrial reactive oxygen species (mtROS) overproduction, enhancing thioredoxin-interacting protein activation and association with NLRP3. Eventually, the NLRP3 inflammasome leads to tubular cell inflammation and pyroptosis. This study revealed the STING-regulated network and further identified the STING/ER stress/mtROS/NLRP3 inflammasome axis as an emerging pathway contributing to tubular damage in LPS-induced AKI. Hence, targeting STING may be a promising therapeutic strategy for preventing septic AKI.

TIGIT regulates CD4+ T cell immunity against polymicrobial sepsis

Background

Sepsis is one of the major causes of death and increased health care burden in modern intensive care units. Immune checkpoints have been prompted to be key modulators of T cell activation, T cell tolerance and T cell exhaustion. This study was designed to investigate the role of the negative immune checkpoint, T cell immunoglobulin and ITIM domain (TIGIT), in the early stage of sepsis.

Method

An experimental murine model of sepsis was developed by cecal ligation and puncture (CLP). TIGIT and CD155 expression in splenocytes at different time points were assessed using flow cytometry. And the phenotypes of TIGIT-deficient (TIGIT-/-) and wild-type (WT) mice were evaluated to explore the engagement of TIGIT in the acute phase of sepsis. In addition, the characteristics were also evaluated in the WT septic mice pretreated with anti-TIGIT antibody. TIGIT and CD155 expression in tissues was measured using real-time quantitative PCR and immunofluorescence staining. Proliferation and effector function of splenic immune cells were evaluated by flow cytometry. Clinical severity and tissue injury were scored to evaluate the function of TIGIT on sepsis. Additionally, tissue injury biomarkers in peripheral blood, as well as bacterial load in peritoneal lavage fluid and liver were also measured.

Results

The expression of TIGIT in splenic T cells and NK cells was significantly elevated at 24 hours post CLP.TIGIT and CD155 mRNA levels were upregulated in sepsis-involved organs when mice were challenged with CLP. In CLP-induced sepsis, CD4+ T cells from TIGIT-/- mice shown increased proliferation potency and cytokine production when compared with that from WT mice. Meanwhile, innate immune system was mobilized in TIGIT-/- mice as indicated by increased proportion of neutrophils and macrophages with potent effector function. In addition, tissue injury and bacteria burden in the peritoneal cavity and liver was reduced in TIGIT-/- mice with CLP induced sepsis. Similar results were observed in mice treated with anti-TIGIT antibody.

Conclusion

TIGIT modulates CD4+ T cell response against polymicrobial sepsis, suggesting that TIGIT could serve as a potential therapeutic target for sepsis.

The Toxic Stress of Racism and Its Relationship to Frailty

Significant morbidity and mortality from COVID-19-related illnesses have been observed among people of color within the United States. While theories involving healthcare inequity and political division have emerged to explain this observation, the role of chronic stress and inflammation is also being explored. Toxic stress is experienced disproportionately by race, ethnicity, and socioeconomic status and increases frailty and vulnerability to diseases such as COVID-19. C-reactive protein (CRP) is a biomarker associated with the inflammatory response that is typically elevated due to exposure to acute or chronic traumatic stress, as well as COVID-19. This study explored the relationship between CRP and Hispanic/non-Hispanic ethnicity among adults hospitalized with COVID-19 via a secondary analysis of retrospective electronic health record (EHR) data collected from a community healthcare system in Southern California. A total of 1,744 cases representing hospitalized adults with COVID-19 were reviewed. Data were extracted from the EHR to reflect demographics, medical diagnoses, medications, CRP, and comorbidity burden. Frequencies, percentages, and measures of central tendency were assessed to understand the distribution of data. Associations were conducted using Pearson's r and the chi-square test of independence. Differences between groups were examined via independent samples t-tests. The sample was 52% Hispanic, 56% male, and the mean age was 62 years (SD = 16.1). The mean age of Hispanic cases was younger than non-Hispanic cases (p < .001, η = 0.289). Serum CRP was significantly higher in the Hispanic cases, with a high degree of association (p < .001, η = 0.472). In addition, higher CRP levels were significantly associated with the need for mechanical ventilation (p < .001, φc = 0.216). No significant relationships were found between CRP and age, body mass index (BMI), or comorbidity burden. Findings challenge the assumption that the disproportionate morbidity and mortality suffered by the Hispanic population due to COVID-19 was due to age, BMI, or comorbidities such as metabolic syndrome or heart disease. CRP in the Hispanic population should be further investigated to understand its relationship to chronic stress, frailty, and risk for COVID-19 in this population.

Advances and Challenges in Sepsis Management: Modern Tools and Future Directions

Sepsis, a critical condition marked by systemic inflammation, profoundly impacts both innate and adaptive immunity, often resulting in lymphopenia. This immune alteration can spare regulatory T cells (Tregs) but significantly affects other lymphocyte subsets, leading to diminished effector functions, altered cytokine profiles, and metabolic changes. The complexity of sepsis stems not only from its pathophysiology but also from the heterogeneity of patient responses, posing significant challenges in developing universally effective therapies. This review emphasizes the importance of phenotyping in sepsis to enhance patient-specific diagnostic and therapeutic strategies. Phenotyping immune cells, which categorizes patients based on clinical and immunological characteristics, is pivotal for tailoring treatment approaches. Flow cytometry emerges as a crucial tool in this endeavor, offering rapid, low cost and detailed analysis of immune cell populations and their functional states. Indeed, this technology facilitates the understanding of immune dysfunctions in sepsis and contributes to the identification of novel biomarkers. Our review underscores the potential of integrating flow cytometry with omics data, machine learning and clinical observations to refine sepsis management, highlighting the shift towards personalized medicine in critical care. This approach could lead to more precise interventions, improving outcomes in this heterogeneously affected patient population.

Defining sepsis in small animals

OBJECTIVE

To discuss the definitions of sepsis in human and veterinary medicine.

DESIGN

International, multicenter position statement on the need for consensus definitions of sepsis in veterinary medicine.

SETTING

Veterinary private practice and university teaching hospitals.

ANIMALS

Dogs and cats.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Sepsis is a life-threatening condition associated with the body's response to an infection. In human medicine, sepsis has been defined by consensus on 3 occasions, most recently in 2016. In veterinary medicine, there is little uniformity in how sepsis is defined and no consensus on how to identify it clinically. Most publications rely on modified criteria derived from the 1991 and 2001 human consensus definitions. There is a divergence between the human and veterinary descriptions of sepsis and no consensus on how to diagnose the syndrome. This impedes research, hampers the translation of pathophysiology insights to the clinic, and limits our abilities to optimize patient care. It may be time to formally define sepsis in veterinary medicine to help the field move forward. In this narrative review, we present a synopsis of prior attempts to define sepsis in human and veterinary medicine, discuss developments in our understanding, and highlight some criticisms and shortcomings of existing schemes.

CONCLUSIONS

This review is intended to serve as the foundation of current efforts to establish a consensus definition for sepsis in small animals and ultimately generate evidence-based criteria for its recognition in veterinary clinical practice.

Nanoparticle-mediated co-delivery of inflammasome inhibitors provides protection against sepsis

The NLRP3 inflammasome, a multiprotein complex responsible for triggering the release of pro-inflammatory cytokines, plays a crucial role in inducing the inflammatory response associated with sepsis. While small molecule inhibitors of the NLRP3 inflammasome have been investigated for sepsis management, delivering NLRP3 inhibitors has been accompanied by several challenges, primarily related to the drug formulation, delivery route, stability, and toxicity. Many existing inflammasome inhibitors either show higher liver toxicity or require a high dosage to efficiently impede the inflammasome complex assembly. Moreover, the potential synergistic effects of combining multiple inflammasome inhibitors in sepsis therapy remain largely unexplored. Therefore, a rational approach is essential for presenting the potential administration of NLRP3 small molecule inhibitors to inhibit NLRP3 inflammasome activation effectively. In this context, we present a lipid nanoparticle-based dual-drug delivery system loaded with MCC 950 and disulfiram, demonstrating markedly higher efficiency compared to an equivalent amount of free-drug combinations and individual drug nanoparticles in vitro. This combination therapy substantially improved the in vivo survival rate of mice for LPS-induced septic peritonitis. Additionally, the synergistic approach illustrated a significant reduction in the expression of active caspase-1 as well as IL-1β inhibition integral components in the NLRP3 pathway. This study underscores the importance of integrating combination therapies facilitated by nanoparticle delivery to address the limitations of small molecule inflammasome inhibitors.

The Ratio of Red Blood Cell Distribution Width to Albumin as a Predictor for Rehospitalization Risk and Rehospitalization All-Cause Mortality in Middle-Aged and Elderly Survivors with Sepsis: An Ambispective ICU Cohort Study

Objective

To explore the relationship between red blood cell distribution width to albumin (RDW/ALB) ratio (RAR) and the risk of rehospitalization and rehospitalization all-cause mortality in middle-aged and elderly survivors with sepsis based on an ambispective longitudinal cohort from the Intensive Care Unit (ICU).

Methods

Between 2017 and 2022, 455 adults who survived the first-episode severe sepsis without recurrence for at least 3 months were included in this study. All participants were followed up every 4 weeks for 12 months. According to the tertiles of RAR, participants were divided into three groups: low-level (≤0.36, n = 152), moderate-level (0.37-0.44, n = 152), and high-level (≥0.45, n = 151). The relationship between RAR and the risk of rehospitalization and rehospitalization all-cause mortality was evaluated.

Results

Out of 455 participants, 156 experienced rehospitalization (34.3%), of which 44 (28.2%) died. Receiver operating characteristic (ROC) analysis showed that the RAR cut-off values for rehospitalization and rehospitalization all-cause mortality were 0.4251 and 0.4743, respectively. Multivariate Cox regression analysis indicated that the RAR was positively associated with rehospitalization (P = 0.011) and all-cause mortality (P = 0.006). Compared with the low-level, the high-level RAR presented a higher dose-dependent rehospitalization risk (P = 0.02) and rehospitalization all-cause mortality (P = 0.044). The stratified analysis displayed that compared to the low-level, with the RAR increasing by 1.0, the risk for rehospitalization increased 3.602-fold in aged <65 patients (P = 0.002) and 1.721-fold in female patients (P = 0.014). Kaplan-Meier survival analysis implied a significant positive association between the RAR and the cumulative incidence of rehospitalization and rehospitalization all-cause mortality (log-rank, all P < 0.001).

Conclusion

RAR has a reliable predictive value for the risk of rehospitalization and rehospitalization all-cause mortality in patients with sepsis. Consequently, monitoring RAR for at least 1 year after surviving sepsis in female patients aged <65 in clinical practice is critical.

Influence of lymphopenia on long-term mortality in septic shock, a retrospective observational study

BACKGROUND AND OBJECTIVE

The diagnosis of infection, to diagnose septic shock, has been qualified by leukocyte counts and protein biomarkers. Septic shock mortality is persistently high (20%-50%), and rising in the long term. The definition of sepsis does not include leukocyte count, and lymphopenia has been associated with its mortality in the short term. Immunosuppression and increased mortality in the long term due to sepsis have not been demonstrated. The aim is to relate the occurrence of lymphopenia and its lack of recovery during septic shock with mortality at 2 years.

PATIENTS AND METHODS

Cohort of 332 elderly patients diagnosed with septic shock. Mortality at 28 days and 2 years was analysed according to leukocyte, neutrophil, and lymphocyte counts, and the ability to recover from lymphopenia (LRec).

RESULTS

A total of 74.1% of patients showed lymphopenia, and 73.5% did not improve during ICU stay. Mortality was 31.0% and 50.3% at 28 days and 2 years, respectively. Lymphopenia was a predictor of early mortality (OR 2.96) and LRec of late mortality (OR 3.98). Long-term mortality was associated with LRec (HR 1.69).

CONCLUSIONS

In elderly patients with septic shock, 28-day mortality is associated with lymphopenia and neutrophilia, and LRec with 2-year mortality; this may represent 2 distinct phenotypes of behaviour after septic shock.

Protein 4.1R regulates M1 macrophages polarization via glycolysis, alleviating sepsis-induced liver injury in mice

Acute liver injury (ALI) is a common clinical disease caused by sepsis, metabolic syndrome, hepatitis virus. Macrophage plays an important role in the development of ALI, which is characterized by polarization and inflammatory regulation. The polarization process of macrophages is related to membrane binding proteins and adaptors. Protein 4.1R acts as an adaptor, linking membrane proteins to the cytoskeleton, and is involved in cell activation and cytokine secretion. However, whether protein 4.1R is involved in regulating macrophage polarization and inflammation-induced liver injury remains unknown. In this study, protein 4.1R is identified with the special effect on macrophage M1 polarization. And it is further demonstrated that protein 4.1R deficiency significantly enhance glycolytic metabolism. Mechanistically, the regulation of protein 4.1R on pyruvate kinase M2 (PKM2) plays a key role in glycolysis metabolism. In addition, we found that protein 4.1R directly interacts with toll-like receptor 4 (TLR4), inhibits the activation of the AKT/HIF-1α signaling pathway. In conclusion, protein 4.1R targets HIF-1α mediated glycolysis regulates M1 macrophage polarization, indicating that protein 4.1R is a candidate for regulating macrophage mediated inflammatory response. In conclusion, we have revealed a novel function of protein 4.1R in macrophage polarization and ALI, providing important insights into the metabolic reprogramming, which is important for ALI therapy. We have revealed a novel function of protein 4.1R in macrophage polarization and ALI, providing important insights into the metabolic reprogramming, which is important for ALI therapy.

The anti-infective and immunologic effect of babassu (Attalea speciosa, Mart. ex Spreng) reduces mortality induced by MRSA-Staphylococcus aureus

ETHNOPHARMACOLOGICAL RELEVANCE

Babassu mesocarp, derived from the Attalea speciosa fruits, is used in folk medicine for infections, inflammatory diseases, and skin wounds.

AIM OF THE STUDY

To investigate the antimicrobial and immunological effect of babassu mesocarp aqueous extract (BAE) in Swiss mice lethally infected with methicillin-resistant Staphylococcus aureus (MRSA).

MATERIALS AND METHODS

The animals (n = 14/group) received an overload of MRSA (3.0 × 108 CFU/mL, via intraperitoneal) and were treated 6 h later with the BAE (125 and 250 mg/kg, subcutaneously). Two experiments were performed with four groups each (Control, ATB, BAE125 and BAE 250). The first was to determine the survival (n = 7 animals/group). The second is to evaluate 24h after infection the number of Colony Forming Units (CFU) and cells in the blood, peritoneum and bronchoalveolar fluid. Cytometric Bead Assay - CBA quantified the cytokines and flow cytometry to determine the cellular distribution in the mesenteric lymph node.

RESULTS

Treatment with BAE improved the survival (60%) in all groups, reduced the number of colony-forming units in the peritoneum and blood, the number of peritoneal and bronchoalveolar cells, and the levels of pro-inflammatory IL-6, TNF-α, and IL-17 cytokines. Additionally, BAE increased: IL-10 and INF-γ levels, nitric oxide release, CD4+ T helper cells, CD14+/IaIe + activated macrophages and Ly6G + neutrophils in the mesenteric lymph node.

CONCLUSIONS

BAE can be used as a complementary treatment during infections due to its antimicrobial and immunomodulatory effect and the ability to protect animals from death after MRSA lethal infection.

Scd-1 deficiency promotes the differentiation of CD8+ T effector

The impact of various fatty acid types on adaptive immunity remains uncertain, and their roles remain unelucidated. Stearoyl-CoA desaturase (Scd) is a Δ-9 desaturase, which is a key rate-limiting enzyme for the conversion of saturated fatty acids (SFA) to monounsaturated fatty acids (MUFA) in the fatty acid de novo synthesis. Scd-1 converts stearic acid (SA) and palmitic acid (PA) to oleic acid (OA) and palmitoleic acid (PO), respectively. In this study, through a series of experiments, we showed that Scd-1 and its resulting compound, OA, have a substantial impact on the transformation of CD8+ naïve T cells into effector T cells. Inactivation of Scd-1 triggers the specialization of CD8+ T cells into the Teff subset, enhancing the effector function and mitochondrial metabolism of Teff cells, and OA can partially counteract this. A deeper understanding of lipid metabolism in immune cells and its impact on cell function can lead to new therapeutic approaches for controlling the immune response and improving prognosis.

Patients with Hemophagocytic Lymphohistiocytosis Who Need Intensive Care Can Be Successfully Rescued by Timely Using Etoposide-Based HLH Regimens

Background

Hemophagocytic lymphohistiocytosis (HLH) patients who need intensive care usually have multiple organ failure and poor prognosis. However, the clinical characteristics, therapeutic efficacy and outcome in these critically ill HLH patients have remained unclear.

Methods

We performed a retrospective study of 50 critically ill HLH patients from September 2013 to October 2022. Patients' information was collected, and the overall survival rate was estimated.

Results

Fifty HLH patients need intensive care, and the median sequential organ failure assessment (SOFA) score was 8. 66.00% patients had septic shock, 60.00% had disseminated intravascular coagulation (DIC) and 56.00% had acute respiratory distress syndrome (ARDS). 64.00% patients needed vasoactive drugs, 60.00% needed invasive or non-invasive positive pressure mechanical ventilation, and 12.00% needed continuous renal replacement therapy (CRRT). Among 18 patients received the etoposide-based regimens, the median time for 17 patients to remove ECG monitoring was 13 days (4-30 days); the median time to remove respiratory support in 10 patients was 8.5 days (4-21 days); the median time for 5 patient to convert from dominant DIC to non-dominant DIC was 4 days (1-14 days) and the median time for 6 patients to stop using vasoactive drugs was 10 days (2-14 days). After 4 weeks of treatment, 7 patients were evaluated as NR, 6 achieved PR, and 5 could not be evaluated. The ORR was 55.56%. Up to the last follow-up, the OS rate of patients receiving etoposide-based regimens was 66.67%. In contrast, all 32 HLH patients in other groups died. Univariate analysis showed that PCT > 0.5 ug/L, PT prolonged > 6 s, TBil > 25umol/L, respiratory failure, renal failure, liver failure and did not receive etoposide- based regimens were the negative factors affecting survival (P = 0.001, 0.017, 0.043, 0.001, 0.000, 0.029, 0.000).

Conclusion

HLH patients who need intensive care timely used etoposide-based HLH regimens might rescue critically ill patients successfully.

Silenced-C5ar1 improved multiple organ injury in sepsis rats via inhibiting neutrophil extracellular trap

Sepsis has a systemic inflammatory response syndrome caused by infection. While neutrophils play contradictory roles in different stages of sepsis. Neutrophils have been proven to play an antibacterial role by producing neutrophil extracellular traps (NETs). Although the NET is beneficial to bacteria resistance, abnormal NET increases tissue damage. The complement C5a receptor 1 (C5ar1) is a gene related to strong inflammatory reactions and is found to be associated with inflammatory factors. This study found that there were 45 down-regulated genes and 704 up-regulated genes in sepsis rats by transcriptome sequencing. And those genes were significantly related to inflammation and immunity by GO and KEGG enrichment analysis involving the chemokine signaling pathway, the Toll-like receptor (TLR) signaling pathway, and the Fc gamma R-mediated phagocytosis. Additionally, the C5ar1 gene was significantly upregulated with interesting potential in sepsis and used for further study. This study used cecum ligation and puncture (CLP) rats that were respectively injected intravenously with PBS or the lentivirus vector to explore the effect of C5ar1 on CLP rats. It demonstrated that silenced- C5ar1 inhibited the ALT, AST, BUN, and CREA levels, improved the lung and spleen injury, and reduced the TNF-α, IL-6, IL-1β, IL-10, cf-DNA, and cfDNA/MPO levels. Additionally, silenced C5ar1 inhibited the TLR2, TLR4, and peptidylarginine deiminase 4 expression levels, which suggested the improvement of silenced C5ar1 on sepsis via inhibiting NETs and the TLR signaling pathway. This study provides a basis and new direction for the study of treatment on sepsis.

The role of platelet P2Y12 receptors in inflammation

Inflammation is a complex pathophysiological process underlying many clinical conditions. Platelets contribute to the thrombo-inflammatory response. Platelet P2Y12 receptors amplify platelet activation, potentiating platelet aggregation, degranulation and shape change. The contents of platelet alpha granules, in particular, act directly on leucocytes, including mediating platelet-leucocyte aggregation and activation via platelet P-selectin. Much evidence for the role of platelet P2Y12 receptors in inflammation comes from studies using antagonists of these receptors, such as the thienopyridines clopidogrel and prasugrel, and the cyclopentyltriazolopyrimidine ticagrelor, in animal and human experimental models. These suggest that antagonism of P2Y12 receptors decreases markers of inflammation with some evidence that this reduces incidence of adverse clinical sequelae during inflammatory conditions. Interpretation is complicated by pleiotropic effects such as those of the thienopyridines on circulating leucocyte numbers and of ticagrelor on adenosine reuptake. The available evidence suggests that P2Y12 receptors are prominent mediators of inflammation and P2Y12 receptor antagonism as a potentially powerful strategy in a broad range of inflammatory conditions. LINKED ARTICLES: This article is part of a themed issue on Platelet purinergic receptor and non-thrombotic disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.4/issuetoc.

Unveiling Dynamic Changes and Regulatory Mechanisms of T Cell Subsets in Sepsis Pathogenesis

Purpose

The pathogenesis of T cell subsets in sepsis during the body's resistance to infection is currently unknown. We aimed to investigate the dynamics and molecular mechanisms of T cells during the development of sepsis.

Patients and Methods

Perform single-cell data analysis on peripheral blood mononuclear cells (PBMCs) specimen samples from seven healthy controls, five early-stage sepsis patients, and four late sepsis patients, and the atlas were mapped and analyzed using reference mapping to identify the T cell subpopulations specific to early sepsis. Expression network upstream to investigate the changes of regulatory transcription factors and pathways by pySCENIC.

Results

Twenty-two CD4+ T-cell subpopulations and 10 CD8+ T-cell subpopulations were identified by mapping analysis. At the early stage of sepsis, we observed altered ratios of multiple immune cells in PBMCs. Three cell types CD4 Tn cells, CD8 (GZMK+ early Tem), and CD8 (ZNF683+CXCR6- Tm) showed an upward trend (p < 0.05) in the early stages of sepsis compared to normal and returned to normal levels after two weeks. In addition, we found the presence of four sepsis-specific transcription factors (MXI1, CHD1, ARID5A, KLF9) in these three types of cells, which were validated in two external datasets. The differentially expressed genes in CD4 Tn cells, CD8 (GZMK+ early Tem), and CD8 (ZNF683+CXCR6- Tm) cells between the healthy group and the early-stage sepsis group are commonly enriched in the allograft rejection pathway. In addition, it was found that CD8 cells exhibit a trend towards differentiation into CD8 Temra cells in sepsis.

Conclusion

We successfully depicted the dynamic changes of T cell subsets during sepsis onset and progression, which provides important clues for an in-depth understanding of T cells' function and regulatory mechanisms during sepsis pathogenesis.

A pairwise cytokine code explains the organism-wide response to sepsis

Sepsis is a systemic response to infection with life-threatening consequences. Our understanding of the molecular and cellular impact of sepsis across organs remains rudimentary. Here, we characterize the pathogenesis of sepsis by measuring dynamic changes in gene expression across organs. To pinpoint molecules controlling organ states in sepsis, we compare the effects of sepsis on organ gene expression to those of 6 singles and 15 pairs of recombinant cytokines. Strikingly, we find that the pairwise effects of tumor necrosis factor plus interleukin (IL)-18, interferon-gamma or IL-1β suffice to mirror the impact of sepsis across tissues. Mechanistically, we map the cellular effects of sepsis and cytokines by computing changes in the abundance of 195 cell types across 9 organs, which we validate by whole-mouse spatial profiling. Our work decodes the cytokine cacophony in sepsis into a pairwise cytokine message capturing the gene, cell and tissue responses of the host to the disease.

Myeloid ACE2 protects against septic hypotension and vascular dysfunction through Ang-(1-7)-Mas-mediated macrophage polarization

Angiotensin converting enzyme 2 (ACE2) is a new identified member of the renin-angiotensin-aldosterone system (RAAS) that cleaves angiotensin II (Ang II) to Ang (1-7), which exerts anti-inflammatory and antioxidative activities via binding with Mas receptor (MasR). However, the functional role of ACE2 in sepsis-related hypotension remains unknown. Our results indicated that sepsis significantly reduced blood pressure and led to disruption between ACE-Ang II and ACE2-Ang (1-7) balance. ACE2 knock-in mice exhibited improved sepsis-induced mortality, hypotension and vascular dysfunction, while ACE2 knockout mice exhibited the opposite effects. Bone marrow transplantation and in vitro experiments confirmed that myeloid ACE2 exerted a protective role by suppressing oxidative stress, NO production and macrophage polarization via the Ang (1-7)-MasR-NF-κB and STAT1 pathways. Thus, ACE2 on myeloid cells could protect against sepsis-mediated hypotension and vascular dysfunction, and upregulating ACE2 may represent a promising therapeutic option for septic patients with hypotension.

A Comprehensive Review of the Immunomodulatory Effects of Vitamin D in Sepsis

Sepsis remains a critical global health challenge characterised by a dysregulated immune response to infection, leading to systemic inflammation and organ dysfunction. This review examines the immunomodulatory effects of Vitamin D in sepsis, focusing on its regulation of immune cell function, modulation of cytokine production, and enhancement of antimicrobial responses. While the potential of Vitamin D as an adjunctive therapy in sepsis management is evident, challenges such as variability in Vitamin D status, uncertainties regarding optimal dosages and patient heterogeneity, and potential adverse effects require careful consideration. The review highlights the implications for future research and clinical practice, emphasising the need for standardised measurement protocols, elucidation of optimal supplementation strategies, and integration of Vitamin D assessments into routine care. Despite the complexities, Vitamin D emerges as a promising avenue for personalised interventions in sepsis, necessitating ongoing research collaboration and evidence-based guidelines to harness its full therapeutic potential and improve clinical outcomes.

PD-L1 Blockade Improves Survival in Sepsis by Reversing Monocyte Dysfunction and Immune Disorder

Monocyte dysfunction is critical to sepsis-induced immunosuppression. Programmed death ligand-1 (PD-L1) has shown a close relationship with inflammatory disorder among animal models and patients. We aimed to investigate the potential beneficial immunologic mechanisms of anti-PD-L1 on monocyte dysfunction of mice with sepsis. Firstly, we assessed the potential association between PD-L1 expression on monocyte subsets and sepsis severity as well as 28-day mortality. In this study, 52 septic patients, 28 septic shock patients, and 40 healthy controls were enrolled and their peripheral whole blood was examined by flow cytometry. Then, cecal ligation and puncture (CLP) were performed for establishing the mouse sepsis model. Subsequently, effects of anti-PD-L1 antibody on monocyte subset, major histocompatibility complex II (MHC II) expression, cytokine production, and survival were investigated. PD-L1 expression on the classical monocytes (CD14 + + CD16 -) was significantly upregulated among septic shock patients and the 28-day death group than non-septic shock group and 28-day survival group (P < 0.05). Compared to septic mice, anti-PD-L1-treated mice had significantly elevated percentages of major histocompatibility complex (MHC) II on peripheral Ly6chi monocyte at 24 h after CLP. Our results showed that the anti-PD-L1 antibody markedly decreased the level of serum inflammatory cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-10 in sepsis mice at 24 h, 48 h, and 72 h, respectively (P < 0.05). The survival rate of CLP mice was significantly improved by anti-PD-L1 antibody treatment. Classical monocytes with high expression of PD-L1 were thought to be connected with sepsis progression. The PD-L1 blockade protects from sepsis, at least partially by inhibiting the reversal of monocyte dysfunction.

Sepsis in elderly patients: the role of neutrophils in pathophysiology and therapy

Sepsis is among the most important causes of mortality, particularly within the elderly population. Sepsis prevalence is on the rise due to different factors, including increasing average population age and the concomitant rise in the prevalence of frailty and chronic morbidities. Recent investigations have unveiled a "trimodal" trajectory for sepsis-related mortality, with the ultimate zenith occurring from 60 to 90 days until several years after the original insult. This prolonged temporal course ostensibly emanates from the sustained perturbation of immune responses, persevering beyond the phase of clinical convalescence. This phenomenon is particularly associated with the aging immune system, characterized by a broad dysregulation commonly known as "inflammaging." Inflammaging associates with a chronic low-grade activation of the innate immune system preventing an appropriate response to infective agents. Notably, during the initial phases of sepsis, neutrophils-essential in combating pathogens-may exhibit compromised activity. Paradoxically, an overly zealous neutrophilic reaction has been observed to underlie multi-organ dysfunction during the later stages of sepsis. Given this scenario, discovering treatments that can enhance neutrophil activity during the early phases of sepsis while curbing their overactivity in the later phases could prove beneficial in fighting pathogens and reducing the detrimental effects caused by an overactive immune system. This narrative review delves into the potential key role of neutrophils in the pathological process of sepsis, focusing on how the aging process impacts their functions, and highlighting possible targets for developing immune-modulatory therapies. Additionally, the review includes tables that outline the principal potential targets for immunomodulating agents.

New insights into the role of mitochondrial metabolic dysregulation and immune infiltration in septic cardiomyopathy by integrated bioinformatics analysis and experimental validation

BACKGROUND

Septic cardiomyopathy (SCM), a common cardiovascular comorbidity of sepsis, has emerged among the leading causes of death in patients with sepsis. SCM's pathogenesis is strongly affected by mitochondrial metabolic dysregulation and immune infiltration disorder. However, the specific mechanisms and their intricate interactions in SCM remain unclear. This study employed bioinformatics analysis and drug discovery approaches to identify the regulatory molecules, distinct functions, and underlying interactions of mitochondrial metabolism and immune microenvironment, along with potential interventional strategies in SCM.

METHODS

GSE79962, GSE171546, and GSE167363 datasets were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) and module genes were identified using Limma and Weighted Correlation Network Analysis (WGCNA), followed by functional enrichment analysis. Machine learning algorithms, including support vector machine-recursive feature elimination (SVM-RFE), least absolute shrinkage and selection operator (LASSO) regression, and random forest, were used to screen mitochondria-related hub genes for early diagnosis of SCM. Subsequently, a nomogram was developed based on six hub genes. The immunological landscape was evaluated by single-sample gene set enrichment analysis (ssGSEA). We also explored the expression pattern of hub genes and distribution of mitochondria/inflammation-related pathways in UMAP plots of single-cell dataset. Potential drugs were explored using the Drug Signatures Database (DSigDB). In vivo and in vitro experiments were performed to validate the pathogenetic mechanism of SCM and the therapeutic efficacy of candidate drugs.

RESULTS

Six hub mitochondria-related DEGs [MitoDEGs; translocase of inner mitochondrial membrane domain-containing 1 (TIMMDC1), mitochondrial ribosomal protein S31 (MRPS31), F-box only protein 7 (FBXO7), phosphatidylglycerophosphate synthase 1 (PGS1), LYR motif containing 7 (LYRM7), and mitochondrial chaperone BCS1 (BCS1L)] were identified. The diagnostic nomogram model based on the six hub genes demonstrated high reliability and validity in both the training and validation sets. The immunological microenvironment differed between SCM and control groups. The Spearman correlation analysis revealed that hub MitoDEGs were significantly associated with the infiltration of immune cells. Upregulated hub genes showed remarkably high expression in the naive/memory B cell, CD14+ monocyte, and plasma cell subgroup, evidenced by the feature plot. The distribution of mitochondria/inflammation-related pathways varied across subgroups among control and SCM individuals. Metformin was predicted to be the most promising drug with the highest combined score. Its efficacy in restoring mitochondrial function and suppressing inflammatory responses has also been validated.

CONCLUSIONS

This study presents a comprehensive mitochondrial metabolism and immune infiltration landscape in SCM, providing a potential novel direction for the pathogenesis and medical intervention of SCM.

Anti-Inflammatory Effects of Idebenone Attenuate LPS-Induced Systemic Inflammatory Diseases by Suppressing NF-κB Activation

Inflammation is a natural protective process through which the immune system responds to injury, infection, or irritation. However, hyperinflammation or long-term inflammatory responses can cause various inflammatory diseases. Although idebenone was initially developed for the treatment of cognitive impairment and dementia, it is currently used to treat various diseases. However, its anti-inflammatory effects and regulatory functions in inflammatory diseases are yet to be elucidated. Therefore, this study aimed to investigate the anti-inflammatory effects of idebenone in cecal ligation puncture-induced sepsis and lipopolysaccharide-induced systemic inflammation. Murine models of cecal ligation puncture-induced sepsis and lipopolysaccharide-induced systemic inflammation were generated, followed by treatment with various concentrations of idebenone. Additionally, lipopolysaccharide-stimulated macrophages were treated with idebenone to elucidate its anti-inflammatory effects at the cellular level. Idebenone treatment significantly improved survival rate, protected against tissue damage, and decreased the expression of inflammatory enzymes and cytokines in mice models of sepsis and systemic inflammation. Additionally, idebenone treatment suppressed inflammatory responses in macrophages, inhibited the NF-κB signaling pathway, reduced reactive oxygen species and lipid peroxidation, and normalized the activities of antioxidant enzyme. Idebenone possesses potential therapeutic application as a novel anti-inflammatory agent in systemic inflammatory diseases and sepsis.

Research progress of hexokinase 2 in inflammatory-related diseases and its inhibitors

Hexokinase 2 (HK2) is a crucial enzyme involved in glycolysis, which converts glucose into glucose-6-phosphate and plays a significant role in glucose metabolism. HK2 can mediate glycolysis, which is linked to the release of inflammatory factors. The over-expression of HK2 increases the production of pro-inflammatory cytokines, exacerbating the inflammatory reaction. Consequently, HK2 is closely linked to various inflammatory-related diseases affecting multiple systems, including the digestive, nervous, circulatory, respiratory, reproductive systems, as well as rheumatoid arthritis. HK2 is regarded as a novel therapeutic target for inflammatory-related diseases, and this article provides a comprehensive review of its roles in these conditions. Furthermore, the development of potent HK2 inhibitors has garnered significant attention in recent years. Therefore, this review also presents a summary of potential HK2 inhibitors, offering promising prospects for the treatment of inflammatory-related diseases in the future.

Potential of piperine for neuroprotection in sepsis-associated encephalopathy

AIMS

Sepsis-associated encephalopathy (SAE) is a common complication that increases mortality and leads to long-term cognitive impairment in sepsis survivors. However, no specific or effective therapy has been identified for this complication. Piperine is an alkaloid known for its anti-inflammatory, antioxidant, and neuroprotective properties, which are important characteristics for treatment of SAE. The objective of this study was to evaluate the neuroprotective effect of piperine on SAE in C57BL/6 mice that underwent cecum ligation and perforation surgery (CLP).

MAIN METHODS

C57BL/6 male mice were randomly assigned to groups that underwent SHAM surgery or CLP. Mice in the CLP group were treated with piperine at doses of 20 or 40 mg/kg for short- (5 days) or long-term (10 days) periods after CLP.

KEY FINDINGS

Our results revealed that untreated septic animals exhibited increased concentrations of IL-6, TNF, VEGF, MMP-9, TBARS, and NLRP3, and decreased levels of BDNF, sulfhydryl groups, and catalase in the short term. Additionally, the levels of carbonylated proteins and degenerated neuronal cells were increased at both time points. Furthermore, short-term and visuospatial memories were impaired. Piperine treatment reduced MMP-9 activity in the short term and decreased the levels of carbonylated proteins and degenerated neuronal cells in the long term. It also lowered IL-6 and TBARS levels at both time points evaluated. Moreover, piperine increased short-term catalase and long-term BDNF factor levels and improved memory at both time points.

SIGNIFICANCE

In conclusion, our data demonstrate that piperine exerts a neuroprotective effect on SAE in animals that have undergone CLP.