Gut-liver crosstalk in sepsis-induced liver injury

MDIVI-1 ALLEVIATES SEPSIS-INDUCED LIVER INJURY BY INHIBITING STING SIGNALING ACTIVATION

ABSTRACT

Proinflammatory hyperactivation of Kupffer cells (KCs) is foremost involved in the pathogenesis of sepsis-induced liver injury. Our previous study found that stimulator of interferon genes (STING) signaling was activated in KCs in response of lipopolysaccharide (LPS) and knocking down dynamin-related protein 1 (DRP1) in KCs effectively inhibited the activation of STING signaling and the subsequent production of proinflammatory cytokines. In this study, we demonstrated that in vivo treatment with mitochondrial division inhibitor 1 (Mdivi-1), a selective inhibitor of DRP1, alleviated cecal ligation and puncture (CLP)-induced liver injury with the improvement of liver pathology and function. Moreover, we found that STING in liver was mainly concentrated in KCs and STING signaling was significantly activated in KCs after CLP. The STING deficiency effectively ameliorated liver injury and decreased the mortality of septic mice, which were reversely worsened by the enhanced activation of STING with DMXAA. The further study showed that Mdivi-1 markedly attenuated STING signaling activation in KCs and inhibited systemic inflammatory response. Importantly, DMXAA application in CLP mice blunted Mdivi-1's liver protection effect. Taken together, our study confirmed Mdivi-1 effectively alleviated CLP-induced liver injury partially through inhibiting STING signaling activation in KCs, which provides new insights and a novel potential pharmacological therapeutic target for treating septic liver injury.

ACE2 Expressed on Myeloid Cells Alleviates Sepsis-Induced Acute Liver Injury via the Ang-(1-7)-Mas Receptor Axis

Sepsis-induced acute liver injury (ALI) is common in intensive care units. Angiotensin-converting enzyme 2 (ACE2) plays a vital role in hepatic fibrosis and steatosis; however, its role in sepsis-induced ALI remains unclear. This study found that hepatic ACE2 expression in cecal ligation and puncture (CLP)-treated mice significantly decreased 24 h after CLP. ACE2-transgenic (TG) mice exhibited a significant improvement in CLP-induced ALI, accompanied by the inhibition of hepatocyte apoptosis, oxidative stress, and inflammation, while ACE2-knockout mice demonstrated an opposite trend. During sepsis-induced ALI, ACE2-TG could also elevate the Ang-(1-7) and Mas receptor (MasR) levels in liver tissues. Interestingly, the MasR inhibitor A779 abrogated the favorable effects of ACE2 on CLP-induced ALI. In a bone marrow transplantation experiment, the ACE2-TG transplantation group showed significantly improved inflammation and liver dysfunction, less hepatocyte apoptosis, and reduced oxidative stress after CLP compared with the wild-type transplantation group. In contrast, the ACE2-knockout group showed poor inflammatory response and liver dysfunction, significantly more hepatocyte apoptosis, and elevated oxidative stress than the wild-type transplantation group after CLP. ACE2 protects against sepsis-induced ALI by inhibiting hepatocyte apoptosis, oxidative stress, and inflammation via the Ang-(1-7)-Mas receptor axis. Thus, targeting ACE2 may be a promising novel strategy for preventing and treating sepsis-induced ALI.

RESEARCH PROGRESS OF CURCUMIN IN THE TREATMENT OF SEPSIS

ABSTRACT

Sepsis is a life-threatening organ dysfunction caused by an unregulated host response to infection. It is an important clinical problem in acute and critical care. In recent years, with the increasing research on the epidemiology, and pathogenesis, diagnostic and therapeutic strategies of sepsis, great progress has been made in clinical practice, but there is still a lack of specific and effective treatment plans. Curcuma longa , a leafy plant of the ginger family, which is a common and safe compound, has multiple pharmacological actions, including, but not limited to, scavenging of oxygen free radicals, attenuation of inflammatory response, and antifibrotic effects. Great progress has been made in the study of sepsis-associated rodent models and in vitro cellular models. However, the evidence of curcumin in the clinical management practice of sepsis is still insufficient; hence, it is very important to systematically summarize the study of curcumin and sepsis pathogenesis.

IRG1/itaconate alleviates acute liver injury in septic mice by suppressing NLRP3 expression and its mediated macrophage pyroptosis via regulation of the Nrf2 pathway

Sepsis, a systemic inflammatory response triggered by infection, has a considerably high mortality rate. However, effective prevention and intervention measures against sepsis remain insufficient. Therefore, this study aimed to investigate the mechanisms underlying the protective properties of immune response gene-1 (IRG1) and 4-Octyl itaconate (OI) during acute liver damage in mice with sepsis. A sepsis mouse model was established to compare wild-type and IRG1-/- groups. The impact of IRG1/Itaconate on pro- and anti-inflammatory cytokines was evaluated using J774A.1 cells. IRG1/Itaconate substantially reduced pro-inflammatory cytokines and increased the release of anti-inflammatory cytokines. It reduced pathological damage to liver tissues, preserved normal liver function, decreased the release of reactive oxygen species (ROS) and LDH, and enhanced the GSH/GSSG ratio. Moreover, IRG1 and itaconic acid activated the Nrf2 signaling pathway, regulating the expression of its downstream antioxidative stress-related proteins. Additionally, they inhibited the activity of NLRP3 inflammatory vesicles to suppress the expression of macrophage-associated pyroptosis signaling molecules. Our findings demonstrate that IRG1/OI inhibits NLRP3 inflammatory vesicle activation and macrophage pyroptosis by modulating the Nrf2 signaling pathway, thereby attenuating acute liver injury in mice with sepsis. These findings could facilitate the clinical application of IRG1/Itaconate to prevent sepsis-induced acute liver injury.

Mendelian randomization analysis reveals causal associations of serum metabolites with sepsis and 28-day mortality

Metabolic disorder has been found to be an important factor in the pathogenesis and progression of sepsis. However, the causation of such an association between serum metabolites and sepsis has not been established. We conducted a two-sample Mendelian randomization (MR) study. A genome-wide association study of 486 human serum metabolites was used as the exposure, whereas sepsis and sepsis mortality within 28 days were set as the outcomes. In MR analysis, 6 serum metabolites were identified to be associated with an increased risk of sepsis, and 6 serum metabolites were found to be related to a reduced risk of sepsis. Furthermore, there were 9 metabolites positively associated with sepsis-related mortality, and 8 metabolites were negatively correlated with sepsis mortality. In addition, "glycolysis/gluconeogenesis" (p = 0.001), and "pyruvate metabolism" (p = 0.042) two metabolic pathways were associated with the incidence of sepsis. This MR study suggested that serum metabolites played significant roles in the pathogenesis of sepsis, which may provide helpful biomarkers for early disease diagnosis, therapeutic interventions, and prognostic assessments for sepsis.

Dachengqi decoction ameliorates sepsis-induced liver injury by inhibiting the TGF-β1/Smad3 pathways

Background

Sepsis-induced acute liver injury (ALI) is a major contributor to mortality in septic patients. Exploring the pathogenesis and developing effective treatment strategies for sepsis-induced ALI is critical for improving patient outcomes. Dachengqi decoction (DCQD), which is a classic Chinese herbal medicine, has been shown to possess potent anti-inflammatory properties. However, the protective effects and underlying mechanisms of DCQD against sepsis-induced ALI remain unclear. This study aimed to investigate the protective effect of DCQD on sepsis-induced ALI and elucidate the involvement of the TGF-1β/Smad3 pathways.

Methods

A septic mouse model was established using caecal ligation and puncture (CLP) to evaluate the protective effect of DCQD on sepsis-induced ALI in vivo. An in vitro cellular inflammation model was established using LPS-stimulated LO2 cells to further investigate the underlying mechanism.

Results

DCQD (2.5, 5.0, and 10.0 g/kg body weight) was administered twice daily for 2 days and exerted a dose-dependent protective effect against sepsis-induced ALI. DCQD treatment significantly inhibited inappropriate inflammatory responses and oxidative stress in liver tissue. Moreover, DCQD maintained liver homeostasis by inhibiting hepatocyte apoptosis and improving sepsis-induced liver damage. In vivo and in vitro studies indicated that the TGF-β1/Smad3 signalling pathway played an important role in sepsis-induced ALI, and DCQD treatment significantly inhibited the activation of this pathway.

Conclusions

DCQD can effectively suppress excessive inflammatory responses and oxidative stress, leading to a substantial reduction in hepatocyte apoptosis in sepsis-induced ALI.

Imp7 siRNA nanoparticles protect against mechanical ventilation-associated liver injury by inhibiting HMGB1 production and NETs formation

Mechanical ventilation (MV) has the potential to induce extra-pulmonary organ damage by adversely affecting the lungs and promoting the secretion of inflammatory cytokines. High-mobility group box 1 protein (HMGB1) is a pro-inflammatory mediator in ventilator-induced lung injury (VILI), but its effect on MV-associated liver injury and the mechanisms are poorly understood. In the present study, mice were subjected to high-volume MV (20 ml/kg) to induce VILI. MV-induced HMGB1 prompted neutrophil extracellular traps (NETs) formation and PANoptosis within the liver. Inhibiting NETs formation by DNase I or PAD4 inhibitor, or by HMGB1 neutralizing ameliorated the liver injury. HMGB1 activated neutrophils to form NETs through TLR4/MyD88/TRAF6 pathway. Importantly, Importin7 siRNA nanoparticles inhibited HMGB1 release and protected against MV-associated liver injury. These data provide evidence of MV-induced HMGB1 prompted NETs formation and PANoptosis in the liver via the TLR4/MyD88/TRAF6 pathway. HMGB1 is a potential therapeutic target for MV-associated liver injury.

Combined metabolomic and proteomic analysis of sepsis related acute liver injury and its pathogenesis research

BACKGROUND

Sepsis-induced acute liver injury is common in patients in intensive care units. However, the exact mechanism of this condition remains unclear. The purpose of this study was to investigate the roles and mechanisms of proteins and metabolites in the liver tissue of mice after sepsis and elucidate the molecular biological mechanisms of sepsis-related liver injury.

METHODS

First, a lipopolysaccharide (LPS)-induced sepsis mouse model was established. Then, according to alanine aminotransferase (ALT) and aspartate aminotransferase (AST) detection in mouse serum and liver histopathological examination (HE) staining, the septic mice were divided into two groups: acute liver injury after sepsis and nonacute liver injury after sepsis. Metabolomics and proteomic analyses were performed on the liver tissues of the two groups of mice to identify significantly different metabolites and proteins. The metabolomics and proteomics results were further analysed to identify the biological indicators and pathogenesis related to the occurrence and development of sepsis-related acute liver injury at the protein and metabolite levels.

RESULTS

A total of 14 differentially expressed proteins and 46 differentially expressed metabolites were identified. Recombinant Erythrocyte Membrane Protein Band 4.2 (Epb42) and adenosine diphosphate (ADP) may be the key proteins and metabolites responsible for sepsis-related acute liver injury, according to the correlation analysis of proteomics and metabolomics. The expression of the differential protein Epb42 was further verified by western blot (WB) detection.

CONCLUSIONS

Our study suggests that the differential protein Epb42 may be key proteins causing sepsis-associated acute liver injury, providing new and valuable information on the possible mechanism of sepsis-associated acute liver injury.

Effect of Transarterial Chemotherapy on the Structure and Function of Gut Microbiota in New Zealand White Rabbits

The gut microbiota (GM) are closely related to hepatocellular carcinoma (HCC) occurrence and development. Furthermore, patients with HCC who have received transcatheter arterial chemoembolization (TACE) treatment often experience adverse gastrointestinal reactions, which may be related to changes in the GM caused by the chemotherapeutic drugs used in TACE. Therefore, we conducted animal experiments to investigate these changes. We analyzed changes in the GM of New Zealand white rabbits treated with hepatic arterial chemotherapy by measuring the levels of serological and colonic tissue markers. Simultaneously, we evaluated the correlation between the GM and these markers to explore the mechanism by which chemotherapy affects the GM. Following transarterial chemotherapy with epirubicin, the Firmicutes abundance decreased, whereas that of Proteobacteria increased. The relative abundance of beneficial bacteria, such as Muribaculaceae, Enterococcus, Ruminococcus, and Clostridia, decreased in the experimental group compared with those in the control group. However, the relative abundance of harmful bacteria, such as Bacteroides and Escherichia (Shigella), was higher in the experimental group than in the control group. Following chemotherapy, the GM of rabbits showed a dynamic change over time, first aggravating and then subsiding. The changes were most notable on the fourth day after surgery and recovered slightly on the seventh day. The changes in the host's GM before and after arterial chemotherapy are evident. Hepatic arterial chemotherapy induces dysbiosis of the intestinal microbiota, disrupts intestinal barrier function, damages the integrity of the intestinal mucosa, increases intestinal permeability, facilitates excessive passage of harmful substances through the gut-liver axis communication between the liver and intestine, and triggers activation of inflammatory pathways such as LPS-TLR-4-pSTAT3, ultimately leading to an inflammatory response. This study provides a theoretical basis for combining TACE with targeted GM intervention to treat HCC and reduce adverse gastrointestinal reactions.

Single-Cell Transcriptomics Reveals the Ameliorative Effect of Oridonin on Septic Liver Injury

Sepsis is a life-threatening syndrome leading to hemodynamic instability and potential organ dysfunction. Oridonin, commonly used in Traditional Chinese Medicine (TCM), exhibits significant anti-inflammation activity. To explore the protective mechanisms of oridonin against the pathophysiological changes, the authors conducted single-cell transcriptome (scRNA-seq) analysis on septic liver models induced by cecal ligation and puncture (CLP). They obtained a total of 63,486 cells, distributed across 11 major cell clusters, and concentrated their analysis on four specific clusters (hepatocytes/Heps, macrophages, endothelial/Endos and T/NK) based on their changes in proportion during sepsis and under oridonin treatment. Firstly, biological changes in Hep, which are related to metabolic dysregulation and pro-inflammatory signaling, are observed during sepsis. Secondly, they uncovered the dynamic profiles of macrophage's phenotype, indicating that a substantial number of macrophages exhibited a M1-skewed phenotype associated with pro-inflammatory characteristics in septic model. Thirdly, they detected an upregulation of both inflammatory cytokines and transcriptomic factor Nfkb1 expression within Endo, along with slight capillarization during sepsis. Moreover, excessive accumulation of cytotoxic NK led to an immune imbalance. Though, oridonin ameliorated inflammatory-related responses and improved the liver dysfunction in septic mice. This study provides fundamental evidence of the protective effects of oridonin against sepsis-induced cytokine storm.

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.

Increased IgA-mediated responses to the gut paracellular pathway and blood-brain barrier proteins predict delirium due to hip fracture in older adults

Introduction

Delirium is accompanied by immune response system activation, which may, in theory, cause a breakdown of the gut barrier and blood-brain barrier (BBB). Some results suggest that the BBB is compromised in delirium, but there is no data regarding the gut barrier. This study investigates whether delirium is associated with impaired BBB and gut barriers in elderly adults undergoing hip fracture surgery.

Methods

We recruited 59 older adults and measured peak Delirium Rating Scale (DRS) scores 2-3 days after surgery, and assessed plasma IgG/IgA levels (using ELISA techniques) for zonulin, occludin, claudin-6, β-catenin, actin (indicating damage to the gut paracellular pathway), claudin-5 and S100B (reflecting BBB damage), bacterial cytolethal distending toxin (CDT), LPS-binding protein (LBP), lipopolysaccharides (LPS), Porphyromonas gingivalis, and Helicobacter pylori.

Results

Results from univariate analyses showed that delirium is linked to increased IgA responses to all the self-epitopes and antigens listed above, except for LPS. Part of the variance (between 45-48.3%) in the peak DRS score measured 2-3 days post-surgery was explained by independent effects of IgA directed to LPS and LBP (or bacterial CDT), baseline DRS scores, and previous mild stroke. Increased IgA reactivity to the paracellular pathway and BBB proteins and bacterial antigens is significantly associated with the activation of M1 macrophage, T helper-1, and 17 cytokine profiles.

Conclusion

Heightened bacterial translocation, disruption of the tight and adherens junctions of the gut and BBB barriers, elevated CDT and LPS load in the bloodstream, and aberrations in cell-cell interactions may be risk factors for delirium.

Transcriptomic profiling of immune cells in murine polymicrobial sepsis

Introduction

Various immune cell types play critical roles in sepsis with numerous distinct subsets exhibiting unique phenotypes even within the same cell population. Single-cell RNA sequencing (scRNA-seq) enables comprehensive transcriptome profiling and unbiased cell classification. In this study, we have unveiled the transcriptomic landscape of immune cells in sepsis through scRNA-seq analysis.

Methods

We induced sepsis in mice by cecal ligation and puncture. 20 h after the surgery, the spleen and peritoneal lavage were collected. Single-cell suspensions were processed using a 10× Genomics pipeline and sequenced on an Illumina platform. Count matrices were generated using the Cell Ranger pipeline, which maps reads to the mouse reference transcriptome, GRCm38/mm10. Subsequent scRNA-seq analysis was performed using the R package Seurat.

Results

After quality control, we subjected the entire data set to unsupervised classification. Four major clusters were identified as neutrophils, macrophages, B cells, and T cells according to their putative markers. Based on the differentially expressed genes, we identified activated pathways in sepsis for each cell type. In neutrophils, pathways related to inflammatory signaling, such as NF-κB and responses to pathogen-associated molecular patterns (PAMPs), cytokines, and hypoxia were activated. In macrophages, activated pathways were the ones related to cell aging, inflammatory signaling, and responses to PAMPs. In B cells, pathways related to endoplasmic reticulum stress were activated. In T cells, activated pathways were the ones related to inflammatory signaling, responses to PAMPs, and acute lung injury. Next, we further classified each cell type into subsets. Neutrophils consisted of four clusters. Some subsets were activated in inflammatory signaling or cell metabolism, whereas others possessed immunoregulatory or aging properties. Macrophages consisted of four clusters, namely, the ones with enhanced aging, lymphocyte activation, extracellular matrix organization, or cytokine activity. B cells consisted of four clusters, including the ones possessing the phenotype of cell maturation or aging. T cells consisted of six clusters, whose phenotypes include molecular translocation or cell activation.

Conclusions

Transcriptomic analysis by scRNA-seq has unveiled a comprehensive spectrum of immune cell responses and distinct subsets in the context of sepsis. These findings are poised to enhance our understanding of sepsis pathophysiology, offering avenues for targeting novel molecules, cells, and pathways to combat infectious diseases.

Potential roles of HSYA in attenuating sepsis-induced liver injury through multi-omics analysis

Liver injury is a strong independent predictor of mortality in patients with sepsis, in which gut dysbiosis plays a crucial role. Hydroxyl safflower yellow A (HSYA), an important component of safflower, has been used to treat liver injury in animal models. However, its role in sepsis-induced liver dysfunction and the specific molecular mechanisms remain unclear. In the current study, we first discussed the discrepancy in the gut microbiota between the cecal ligation puncture (CLP) and HSYA groups using 16 S RNA sequencing. Our data demonstrated that HSYA supplementation significantly decreased the relative abundance of Proteobacteria, Firmicutes, and Campylobacterota, and further decreased the abundance of Bacteroidota, suggesting that the protective effects of HSYA against sepsis-induced liver injury may be partially attributed to the alteration of these bacteria. In addition, the metabolomic data identified 823 differentially expressed metabolites associated with sepsis-induced liver injury. After HSYA supplementation, the levels of 56 metabolites were restored to sham-like levels. Transcriptomic analysis revealed 4990 differentially expressed genes (DEGs) between the sham and CLP groups, and after HSYA injection, 1613 genes were modulated. Comprehensive analysis demonstrated that the enrichment pathways of the 903 DEGs mainly focused on inflammatory responses, amino acid metabolism, and Lipid reactions. In conclusion, our study revealed the potential mechanism of action of HSYA in sepsis-induced liver injury through a comprehensive analysis of 16 S RNA sequencing, metabolomics, and transcriptomics, thus providing a theoretical basis for further clinical applications of HSYA.

ASTRAGALOSIDE Ⅳ MODULATES GUT MACROPHAGES M1/M2 POLARIZATION BY RESHAPING GUT MICROBIOTA AND SHORT CHAIN FATTY ACIDS IN SEPSIS

ABSTRACT

M1 macrophage-mediated inflammation is critical in sepsis. We previously found the protective role of astragaloside intravenous (AS-IV) in sepsis-associated gut impairment, whose specific mechanism remains unknown. Gut microbiota modulates gut homeostatic balance to avoid excessive inflammation. Here, we aimed to investigate effects of AS-IV on gut macrophages polarization and potential roles of gut microbiota and short chain fatty acids (SCFAs) in septic gut damage. Mice were pretreated by AS-IV gavage for 7 days before cecal ligation and puncture. M1 polarization of gut lamina propria macrophages (LpMs) was promoted by cecal ligation and puncture, accompanied by abnormal cytokines release and intestinal barrier dysfunction. NLRP3 inflammasome was activated in M1 LpMs. 16S rRNA sequencing demonstrated gut microbiota imbalance. The levels of acetate, propionate, and butyrate in fecal samples decreased. Notably, AS-IV reversed LpMs M1/M2 polarization, lightened gut inflammation and barrier injury, reduced NLRP3 inflammasome expression in LpMs, restored the diversity of gut microbiome, and increased butyrate levels. Similarly, these benefits were mimicked by fecal microbiota transplantation or exogenous butyrate supplementation. In Caco-2 and THP-1 cocultured model, LPS and interferon γ caused THP-1 M1 polarization, Caco-2 barrier impairment, abnormal cytokines release, and high NLRP3 inflammasome expression in THP-1 cells, all of which were mitigated by butyrate administration. However, these protective effects of butyrate were abrogated by NLRP3 gene overexpression in THP-1. In conclusion, AS-IV can ameliorate sepsis-induced gut inflammation and barrier dysfunction by modulating M1/M2 polarization of gut macrophages, whose underlying mechanism may be restoring gut microbiome and SCFA to restrain NLRP3 inflammasome activation.

Argon inhalation attenuates systemic inflammation and rescues lung architecture during experimental neonatal sepsis

PURPOSE

Neonatal sepsis is a systemic inflammatory infection common in premature infants and a leading cause of mortality. Argon is an emerging interest in the field of noble gas therapy. Neonates with severe sepsis are frequently mechanically ventilated creating an opportunity for inhalation therapy. We aimed to investigate argon inhalation as a novel experimental therapy in neonatal sepsis.

METHODS

Sepsis was established in C57BL/6 neonatal mice by a lipopolysaccharide intraperitoneal injection on postnatal day 9. Septic pup mice were exposed to room air as well as non-septic controls. In the argon group, septic pup mice were exposed to argon (70% Ar, 30% O2) for 6 h in a temperature-controlled environment.

RESULTS

At 6 h, survival was significantly enhanced when septic mice received argon compared to septic controls. Serum profiles of cytokine release were significantly attenuated as well as lung architecture restored.

CONCLUSIONS

Our findings suggest that argon inhalation as a novel treatment for neonatal sepsis, reducing mortality and counteracting the acute systemic inflammatory response in the blood and preserving the architecture of the lung. This research can contribute to a paradigm shift in the treatment and outcome of neonates with sepsis.

Novel tripeptide RKH derived from Akkermansia muciniphila protects against lethal sepsis

OBJECTIVE

The pathogenesis of sepsis is complex, and the sepsis-induced systemic proinflammatory phase is one of the key drivers of organ failure and consequent mortality. Akkermansia muciniphila (AKK) is recognised as a functional probiotic strain that exerts beneficial effects on the progression of many diseases; however, whether AKK participates in sepsis pathogenesis is still unclear. Here, we evaluated the potential contribution of AKK to lethal sepsis development.

DESIGN

Relative abundance of gut microbial AKK in septic patients was evaluated. Cecal ligation and puncture (CLP) surgery and lipopolysaccharide (LPS) injection were employed to establish sepsis in mice. Non-targeted and targeted metabolomics analysis were used for metabolites analysis.

RESULTS

We first found that the relative abundance of gut microbial AKK in septic patients was significantly reduced compared with that in non-septic controls. Live AKK supplementation, as well as supplementation with its culture supernatant, remarkably reduced sepsis-induced mortality in sepsis models. Metabolomics analysis and germ-free mouse validation experiments revealed that live AKK was able to generate a novel tripeptide Arg-Lys-His (RKH). RKH exerted protective effects against sepsis-induced death and organ damage. Furthermore, RKH markedly reduced sepsis-induced inflammatory cell activation and proinflammatory factor overproduction. A mechanistic study revealed that RKH could directly bind to Toll-like receptor 4 (TLR4) and block TLR4 signal transduction in immune cells. Finally, we validated the preventive effects of RKH against sepsis-induced systemic inflammation and organ damage in a piglet model.

CONCLUSION

We revealed that a novel tripeptide, RKH, derived from live AKK, may act as a novel endogenous antagonist for TLR4. RKH may serve as a novel potential therapeutic approach to combat lethal sepsis after successfully translating its efficacy into clinical practice.

Effects of enteral nutrition supplemented with octanoic acid on lipopolysaccharide-induced intestinal injury: role of peroxisome proliferator-activated receptor γ/STAT-1/myeloid differentiation factor 88 pathway

OBJECTIVE

Enteral nutrition is the key therapy in septic patients. Different formulas of enteral nutrition have various effects on gastrointestinal sepsis. Therefore, we investigated the effects of enteral nutrition supplemented with octanoic acid on lipopolysaccharide-induced intestinal injury and explored the potential mechanism.

METHODS

First, to investigate the effects of enteral nutrition supplemented with octanoic acid on lipopolysaccharide-induced intestinal injury, rats were randomly divided into four groups: sham, lipopolysaccharide, lipopolysaccharide + enteral nutrition, and lipopolysaccharide + enteral nutrition + octanoic acid. Then, to explore whether enteral nutrition supplemented with octanoic acid can prevent lipopolysaccharide-induced intestinal injury via the peroxisome proliferator-activated receptor γ/STAT-1/myeloid differentiation factor 88 pathway, rats were randomly divided into five groups: sham, lipopolysaccharide, lipopolysaccharide + enteral nutrition + octanoic acid, lipopolysaccharide + enteral nutrition + octanoic acid + SR202, and lipopolysaccharide + pioglitazone. All rats received nutritional support for 3 d. We examined the serum levels of inflammatory factors, pathologic changes, goblet cell density, intestinal tight junction protein expression, and the peroxisome proliferator-activated receptor γ/STAT-1/myeloid differentiation factor 88 pathway in the ileum and colon. The effect of octanoic acid on intestinal epithelium injury was also explored in vitro.

RESULTS

Enteral nutrition supplemented with octanoic acid significantly decreased the serum levels of inflammatory factors and prevented intestinal barrier dysfunction compared with enteral nutrition alone (P < 0.05). Inhibiting the peroxisome proliferator-activated receptor γ/STAT-1/myeloid differentiation factor 88 pathway exacerbated effects of enteral nutrition supplemented with octanoic acid on intestinal injury (P < 0.05). Activation of the peroxisome proliferator-activated receptor γ/STAT-1/myeloid differentiation factor 88 pathway prevented intestinal injury (P < 0.05). Octanoic acid also exerted a similar effect on intestinal epithelium injury in vitro.

CONCLUSIONS

Enteral nutrition supplemented with octanoic acid prevents lipopolysaccharide-induced intestinal injury via the peroxisome proliferator-activated receptor γ/STAT-1/myeloid differentiation factor 88 pathway.

Early gut microbiological changes and metabolomic changes in patients with sepsis: a preliminary study

The gut microbiota is closely related to the development of sepsis. The aim of this study was to explore changes in the gut microbiota and gut metabolism, as well as potential relationships between the gut microbiota and environmental factors in the early stages of sepsis. Fecal samples were collected from 10 septic patients on the first and third days following diagnosis in this study. The results showed that in the early stages of sepsis, the gut microbiota is dominated by microorganisms that are tightly associated with inflammation, such as Escherichia-Shigella, Enterococcus, Enterobacteriaceae, and Streptococcus. On sepsis day 3 compared to day 1, there was a significant decrease in Lactobacillus and Bacteroides and a significant increase in Enterobacteriaceae, Streptococcus, and Parabacteroides. Culturomica_massiliensis, Prevotella_7 spp., Prevotellaceae, and Pediococcus showed significant differences in abundance on sepsis day 1, but not on sepsis day 3. Additionally, 2-keto-isovaleric acid 1 and 4-hydroxy-6-methyl-2-pyrone metabolites significantly increased on sepsis day 3 compared to day 1. Prevotella_7 spp. was positively correlated with phosphate and negatively correlated with 2-keto-isovaleric acid 1 and 3-hydroxypropionic acid 1, while Prevotella_9 spp. was positively correlated with sequential organ failure assessment score, procalcitonin and intensive care unit stay time. In conclusion, the gut microbiota and metabolites are altered during sepsis, with some beneficial microorganisms decreasing and some pathogenic microorganisms increasing. Furthermore, Prevotellaceae members may play different roles in the intestinal tract, with Prevotella_7 spp. potentially possessing beneficial health properties and Prevotella_9 spp. potentially playing a promoting role in sepsis.

Maresin1 prevents sepsis-induced acute liver injury by suppressing NF-κB/Stat3/MAPK pathways, mitigating inflammation

Aims

The treatment of sepsis remains challenging and the liver is a non-neglectful target of sepsis-induced injury. Uncontrolled inflammatory responses exert a central role in the pathophysiological process of sepsis-induced acute liver injury (SI-ALI). Maresin1 (MaR1) is a derivative of omega-3 docosahexaenoic acid (DHA), which has been shown to have anti-inflammatory effects and is effective in a variety of sepsis-related diseases. This study aimed to determine the effect of MaR1 on cecal ligation and puncture (CLP)-caused SI-ALI and explore its possible mechanisms.

Main methods

Mice were subjected to CLP, and then intravenously injected via tail vein with low-dose MaR1 (0.5 ng, 200 μL) or high-dose MaR1 (1 ng, 200 μL) or sterile normal saline (NS) (200 μL) 1 h later. Then, the survival rate, body weight change, liver function, bacterial load, neutrophil infiltration, and inflammatory cytokines were detected.

Results

MaR1 significantly increased the 7-day survival rate and reduced the bacterial load in peritoneal lavage fluid and blood in a dose-dependent manner in mice with SI-ALI. Treatment with MaR1 could also restore the function of the liver in septic mice. Besides, MaR1 exerted anti-inflammatory effects by decreasing the expression of pro-inflammatory molecules (TNF-α, IL-6 and IL-1β), bacterial load, and neutrophil infiltration and increasing the expression of anti-inflammatory molecules (IL-10).

Significance

Our experimental results showed that MaR1 alleviated liver injury induced by sepsis. This work highlighted a potential clinic use of MaR1 in treating acute inflammation of SI-ALI, but also provided new insight into the underlying molecular mechanism.

Effect of Early Enteral Nutrition on Graft Loss After Living Donor Liver Transplantation: A Propensity Score Matching Analysis

BACKGROUND

This study aimed to elucidate the effect of early enteral nutrition on graft loss within 12 h after living-donor liver transplantation (LDLT) using propensity score-matching analysis and subsequently examine the risk factors for graft loss after LDLT.

METHODS

We retrospectively reviewed the data of 467 LDLT patients who were assigned to the early and non-early groups based on the optimal cutoff value of 12 h for the starting time of early enteral nutrition after LDLT to predict graft loss.

RESULTS

The 1-year graft survival rate of the early group before propensity score-matching was 92.1%, whereas the 1-year graft survival rate of the non-early group was 86.2%. There was no significant difference between the 2 groups (P = .067). The incidences of early allograft dysfunction (EAD), small-for-size graft (SFSG) syndrome, acute cellular rejection (ACR), and sepsis were not statistically different between the 2 groups (P = .12, .91, .46, and .056, respectively). After propensity score-matching, the 1-year graft survival rate of the early group was 94.4%, whereas the 1-year graft survival rate of the non-early group was 85.4% (P = .034). The incidences of EAD, SFSG syndrome, and ACR were not statistically different between the 2 groups (P = .43, .81, and .24, respectively). However, the incidence of sepsis was statistically different between the 2 groups (non-early: 10.7% vs early: 3.6%, P = .038).

CONCLUSION

Early enteral nutrition within 12 h after LDLT may contribute to better graft survival in LDLT patients by preventing sepsis.

The roles of tissue-resident macrophages in sepsis-associated organ dysfunction

Sepsis, a syndrome caused by a dysregulated host response to infection and characterized by life-threatening organ dysfunction, particularly septic shock and sepsis-associated organ dysfunction (SAOD), is a medical emergency associated with high morbidity, high mortality, and long-term sequelae. Tissue-resident macrophages (TRMs) are a subpopulation of macrophages derived primarily from yolk sac progenitors and fetal liver during embryogenesis, located primarily in non-lymphoid tissues in adulthood, capable of local self-renewal independent of hematopoiesis, and developmentally and functionally restricted to the non-lymphoid organs in which they reside. TRMs are the first line of defense against life-threatening conditions such as sepsis, tumor growth, traumatic-associated organ injury, and surgical-associated injury. In the context of sepsis, TRMs can be considered as angels or demons involved in organ injury. Our proposal is that sepsis, septic shock, and SAOD can be attenuated by modulating TRMs in different organs. This review summarizes the pathophysiological mechanisms of TRMs in different organs or tissues involved in the development and progression of sepsis.

Risk Factor Analysis and Nomogram for Predicting In-Hospital Mortality in ICU Patients with Heat Stroke: A National Multicenter Study

Objective

The aim of this nationwide multicenter study was to ascertain the risk factors associated with in-hospital mortality in patients with heat stroke admitted to intensive care units (ICUs) and to develop a nomogram for prognostic prediction.

Methods

A retrospective analysis was conducted on clinical data collected from ICU patients diagnosed with heat stroke across multiple centers nationwide. Univariate and multivariate logistic regression analyses were performed to identify significant risk factors for in-hospital mortality. Based on the results of the multivariate analysis, a nomogram was constructed to estimate the individualized probability of mortality. Internal validation of the nomogram was performed, and its performance was assessed using receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA).

Results

A total of 292 ICU patients with heat stroke were included in this study. Three risk factors, namely Cr (creatinine), AST (aspartate aminotransferase), and SBP (systolic blood pressure), were found to be significantly associated with in-hospital mortality. These risk factors were incorporated into the nomogram, which exhibited good discriminative ability (area under the ROC curve of the training and validation cohorts were 0.763 and 0.739, respectively) and calibration. Internal validation and decision curve analysis confirmed the stability and reliability of the nomogram.

Conclusion

This nationwide multicenter study identified key risk factors for in-hospital mortality in ICU patients with heat stroke. The developed nomogram provides an individualized prediction of mortality risk and can serve as a valuable tool for clinicians in the assessment and management of ICU patients with heat stroke.

Advances in Mesenchymal stem cells regulating macrophage polarization and treatment of sepsis-induced liver injury

Sepsis is a syndrome of dysregulated host response caused by infection, which leads to life-threatening organ dysfunction. It is a familiar reason of death in critically ill patients. Liver injury frequently occurs in septic patients, yet the development of targeted and effective treatment strategies remains a pressing challenge. Macrophages are essential parts of immunity system. M1 macrophages drive inflammation, whereas M2 macrophages possess anti-inflammatory properties and contribute to tissue repair processes. Mesenchymal stem cells (MSCs), known for their remarkable attributes including homing capabilities, immunomodulation, anti-inflammatory effects, and tissue regeneration potential, hold promise in enhancing the prognosis of sepsis-induced liver injury by harmonizing the delicate balance of M1/M2 macrophage polarization. This review discusses the mechanisms by which MSCs regulate macrophage polarization, alongside the signaling pathways involved, providing an idea for innovative directions in the treatment of sepsis-induced liver injury.

Heparanase inhibition leads to improvement in patients with acute gastrointestinal injuries induced by sepsis

BACKGROUND

Patients with sepsis are at high risk for acute gastrointestinal injury (AGI), but the diagnosis and treatment of AGI due to sepsis are unsatisfactory. Heparanase (HPA) plays an important role in septic AGI (S-AGI), but its specific mechanism is not completely understood, and few clinical reports are available.

AIM

To explore the effect and mechanism of HPA inhibition in S-AGI patients.

METHODS

In our prospective clinical trial, 48 patients with S-AGI were randomly assigned to a control group to receive conventional treatment, whereas 47 patients were randomly assigned to an intervention group to receive conventional treatment combined with low molecular weight heparin. AGI grade, sequential organ failure assessment score, acute physiology and chronic health evaluation II score, D-dimer, activated partial thromboplastin time (APTT), anti-Xa factor, interleukin-6, tumour necrosis factor-α, HPA, syndecan-1 (SDC-1), LC3B (autophagy marker), intestinal fatty acid binding protein, D-lactate, motilin, gastrin, CD4/CD8, length of intensive care unit (ICU) stay, length of hospital stay and 28-d survival on the 1st, 3rd and 7th d after treatment were compared. Correlations between HPA and AGI grading as well as LC3B were compared. Receiver operator characteristic (ROC) curves were generated to evaluate the diagnostic value of HPA, intestinal fatty acid binding protein and D-lactate in S-AGI.

RESULTS

Serum HPA and SCD-1 levels were significantly reduced in the intervention group compared with the control group (P < 0.05). In addition, intestinal fatty acid-binding protein, D-lactate, AGI grade, motilin, and gastrin levels and sequential organ failure assessment score were significantly decreased (P < 0.05) in the intervention group. However, LC3B, APTT, anti-Xa factor, and CD4/CD8 were significantly increased (P < 0.05) in the intervention group. No significant differences in interleukin-6, tumour necrosis factor-α, d-dimer, acute physiology and chronic health evaluation II score, length of ICU stay, length of hospital stay, or 28-d survival were noted between the two groups (P > 0.05). Correlation analysis revealed a significant negative correlation between HPA and LC3B and a significant positive correlation between HPA and AGI grade. ROC curve analysis showed that HPA had higher specificity and sensitivity in diagnosis of S-AGI.

CONCLUSION

HPA has great potential as a diagnostic marker for S-AGI. Inhibition of HPA activity reduces SDC-1 shedding and alleviates S-AGI symptoms. The inhibitory effect of HPA in gastrointestinal protection may be achieved by enhanced autophagy.

Systemic cytokines inhibition with Imp7 siRNA nanoparticle ameliorates gut injury in a mouse model of ventilator-induced lung injury

Mechanical ventilation (MV) may negatively affect the lungs and cause the release of inflammatory mediators, resulting in extra-pulmonary organ dysfunction. Studies have revealed systemically elevated levels of proinflammatory cytokines in animal models of ventilator-induced lung injury (VILI); however, whether these cytokines have an effect on gut injury and the mechanisms involved remain unknown. In this study, VILI was generated in mice with high tidal volume mechanical ventilation (20 ml/kg). Tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 concentrations in serum and gut measured by ELISA showed significant elevation in the VILI mice. Significant increases in gut injury and PANoptosis were observed in the VILI mice, which were positively correlated with the serum levels of TNF-α, IL-1β, and IL-6. The VILI mice displayed intestinal barrier defects, decreased expressions of occludin and zonula occludin-1 (ZO-1), and increased expression of claudin-2 and the activation of myosin light chain (MLC). Importantly, intratracheal administration of Imp7 siRNA nanoparticle effectively inhibited cytokines production and protected mice from VILI-induced gut injury. These data provide evidence of systemic cytokines contributing to gut injury following VILI and highlight the possibility of targeting cytokines inhibition via Imp7 siRNA nanoparticle as a potential therapeutic intervention for alleviating gut injury following VILI.

Single-cell RNA sequencing deciphers the mechanism of sepsis-induced liver injury and the therapeutic effects of artesunate

Liver, as an immune and detoxification organ, represents an important line of defense against bacteria and infection and a vulnerable organ that is easily injured during sepsis. Artesunate (ART) is an anti-malaria agent, that also exhibits broad pharmacological activities including anti-inflammatory, immune-regulation and liver protection. In this study, we investigated the cellular responses in liver to sepsis infection and ART hepatic-protective mechanisms against sepsis. Cecal ligation and puncture (CLP)-induced sepsis model was established in mice. The mice were administered ART (10 mg/kg, i.p.) at 4 h, and sacrificed at 12 h after the surgery. Liver samples were collected for preparing single-cell RNA transcriptome sequencing (scRNA-seq). The scRNA-seq analysis revealed that sepsis-induced a dramatic reduction of hepatic endothelial cells, especially the subtypes characterized with proliferation and differentiation. Macrophages were recruited during sepsis and released inflammatory cytokines (Tnf, Il1b, Il6), chemokines (Ccl6, Cd14), and transcription factor (Nfkb1), resulting in liver inflammatory responses. Massive apoptosis of lymphocytes and abnormal recruitment of neutrophils caused immune dysfunction. ART treatment significantly improved the survival of CLP mice within 96 h, and partially relieved or reversed the above-mentioned pathological features, mitigating the impact of sepsis on liver injury, inflammation, and dysfunction. This study provides comprehensive fundamental proof for the liver protective efficacy of ART against sepsis infection, which would potentially contribute to its clinical translation for sepsis therapy. Single cell transcriptome reveals the changes of various hepatocyte subtypes of CLP-induced liver injury and the potential pharmacological effects of artesunate on sepsis.

Liraglutide pretreatment attenuates sepsis-induced acute lung injury

There are no effective targeted therapies to treat acute respiratory distress syndrome (ARDS). Recently, the commonly used diabetes and obesity medications, glucagon-like peptide-1 (GLP-1) receptor agonists, have been found to have anti-inflammatory properties. We, therefore, hypothesized that liraglutide pretreatment would attenuate murine sepsis-induced acute lung injury (ALI). We used a two-hit model of ALI (sepsis+hyperoxia). Sepsis was induced by intraperitoneal injection of cecal slurry (CS; 2.4 mg/g) or 5% dextrose (control) followed by hyperoxia [HO; fraction of inspired oxygen ([Formula: see text]) = 0.95] or room air (control; [Formula: see text] = 0.21). Mice were pretreated twice daily with subcutaneous injections of liraglutide (0.1 mg/kg) or saline for 3 days before initiation of CS+HO. At 24-h post CS+HO, physiological dysfunction was measured by weight loss, severity of illness score, and survival. Animals were euthanized, and bronchoalveolar lavage (BAL) fluid, lung, and spleen tissues were collected. Bacterial burden was assessed in the lung and spleen. Lung inflammation was assessed by BAL inflammatory cell numbers, cytokine concentrations, lung tissue myeloperoxidase activity, and cytokine expression. Disruption of the alveolar-capillary barrier was measured by lung wet-to-dry weight ratios, BAL protein, and epithelial injury markers (receptor for advanced glycation end products and sulfated glycosaminoglycans). Histological evidence of lung injury was quantified using a five-point score with four parameters: inflammation, edema, septal thickening, and red blood cells (RBCs) in the alveolar space. Compared with saline treatment, liraglutide improved sepsis-induced physiological dysfunction and reduced lung inflammation, alveolar-capillary barrier disruption, and lung injury. GLP-1 receptor activation may hold promise as a novel treatment strategy for sepsis-induced ARDS. Additional studies are needed to better elucidate its mechanism of action.NEW & NOTEWORTHY In this study, pretreatment with liraglutide, a commonly used diabetes medication and glucagon-like peptide-1 (GLP-1) receptor agonist, attenuated sepsis-induced acute lung injury in a two-hit mouse model (sepsis + hyperoxia). Septic mice who received the drug were less sick, lived longer, and displayed reduced lung inflammation, edema, and injury. These therapeutic effects were not dependent on weight loss. GLP-1 receptor activation may hold promise as a new treatment strategy for sepsis-induced acute respiratory distress syndrome.

Roquin-1 resolves sepsis-associated acute liver injury by regulating inflammatory profiles via miRNA cargo in extracellular vesicles

Sepsis-associated acute liver injury (SALI) is an independent risk for sepsis-induced death orchestrated by innate and adaptive immune responses. Here, we found that Roquin-1 was decreased during SALI and expressed mainly in monocyte-derived macrophages. Meanwhile, Roquin-1 was correlated with the inflammatory profiles in humans and mice. Mechanically, Roquin-1 in macrophages promoted Ago2-K258-ubiquitination and inhibited Ago2-S387/S828-phosphorylation. Ago2-S387-phosphorylation inhibited Ago2-miRNA's complex location in multivesicular bodies and sorting in macrophages-derived extracellular vesicles (MDEVs), while Ago2-S828-phosphorylation modulated the binding between Ago2 and miRNAs by special miRNAs-motifs. Then, the anti-inflammatory miRNAs in MDEVs decreased TSC22D2 expression directly, upregulated Tregs-differentiation via TSC22D2-STAT3 signaling, and inhibited M1-macrophage-polarization by TSC22D2-AMPKα-mTOR pathway. Furthermore, WT MDEVs in mice alleviated SALI by increasing Tregs ratio and decreasing M1-macrophage frequency synchronously. Our study showed that Roquin-1 in macrophages increased Tregs-differentiation and decreased M1-macrophage-polarization simultaneously via miRNA in MDEVs, suggesting Roquin-1 can be used as a potential tool for SALI treatment and MDEVs engineering.

Nobiletin protects against ferroptosis to alleviate sepsis-associated acute liver injury by modulating the gut microbiota

Nobiletin (NOB), a plant-based polymethoxyflavone, is a promising protective agent against sepsis; yet the mechanisms were not fully elucidated. The gut microbiota is found to be strongly associated with sepsis-associated acute liver injury (SALI). Here, our study aimed to evaluate the protective effect of NOB on SALI and explore the underlying molecular mechanisms. Cecal ligation and puncture (CLP) was used to induce SALI in mice. NOB was administered by gavage for 7 days before CLP induction. The 16S rRNA gene sequencing and fecal microbiota transplantation (FMT) were performed to verify the function of the gut microbiota. The markers of ferroptosis, inflammation, gut microbiota composition, and liver injury were determined. NOB administration significantly alleviated hepatic ferroptosis and inflammation in septic mice. Meanwhile, NOB upregulated the expression levels of nuclear factor E2-related factor 2 (Nrf2) and its downstream protein heme oxygenase-1 (HO-1). The protective effect of NOB administration against ferroptosis in SALI mice was reversed by the Nrf2 inhibitor ML385. Additionally, increased abundances of Ligilactobacillus, Akkermansia, and Lactobacillus, and decreased abundances of Dubosiella and Bacteroides in the gut were observed under NOB administration, suggesting that NOB might modulate the gut microbiota composition of septic mice. Furthermore, gut microbiota ablation by antibiotic treatment partly reversed the protective effects of NOB on sepsis. FMT also confirmed that NOB inhibited ferroptosis and activated Nrf2 signalling in SALI mice by modulating the gut microbiota. These results revealed that, by modulating the gut microbiota, NOB attenuated ferroptosis in septic liver injury through upregulating Nrf2-Gpx4. Our findings provide novel insights into microbiome-based therapeutic approaches for sepsis.

USP5 promotes lipopolysaccharide-induced apoptosis and inflammatory response by stabilizing the TXNIP protein

BACKGROUND

The role of thioredoxin-interacting protein (TXNIP) in lipopolysaccharide-induced liver injury in mice has been reported, but the underlying mechanisms are poorly understood.

METHODS

We overexpressed deubiquitinase in cells overexpressing TXNIP and then detected the level of TXNIP to screen out the deubiquitinase regulating TXNIP; the interaction between TXNIP and deubiquitinase was verified by coimmunoprecipitation. After knockdown of a deubiquitinase and overexpression of TXNIP in Huh7 and HepG2 cells, lipopolysaccharide was used to establish a cellular inflammatory model to explore the role of deubiquitinase and TXNIP in hepatocyte inflammation.

RESULTS

In this study, we discovered that ubiquitin-specific protease 5 (USP5) interacts with TXNIP and stabilizes it through deubiquitylation in Huh-7 and HepG2 cells after treatment with lipopolysaccharide. In lipopolysaccharide-treated Huh-7 and HepG2 cells, USP5 knockdown increased cell viability, reduced apoptosis, and decreased the expression of inflammatory factors, including NLRP3, IL-1β, IL-18, ASC, and procaspase-1. Overexpression of TXNIP reversed the phenotype induced by knockdown USP5.

CONCLUSIONS

In summary, USP5 promotes lipopolysaccharide-induced apoptosis and inflammatory response by stabilizing the TXNIP protein.

Single-cell transcriptome analysis uncovers underlying mechanisms of acute liver injury induced by tripterygium glycosides tablet in mice

Tripterygium glycosides tablet (TGT), the classical commercial drug of Tripterygium wilfordii Hook. F. has been effectively used in the treatment of rheumatoid arthritis, nephrotic syndrome, leprosy, Behcet's syndrome, leprosy reaction and autoimmune hepatitis. However, due to its narrow and limited treatment window, TGT-induced organ toxicity (among which liver injury accounts for about 40% of clinical reports) has gained increasing attention. The present study aimed to clarify the cellular and molecular events underlying TGT-induced acute liver injury using single-cell RNA sequencing (scRNA-seq) technology. The TGT-induced acute liver injury mouse model was constructed through short-term TGT exposure and further verified by hematoxylin-eosin staining and liver function-related serum indicators, including alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and total bilirubin. Using the mouse model, we identified 15 specific subtypes of cells in the liver tissue, including endothelial cells, hepatocytes, cholangiocytes, and hepatic stellate cells. Further analysis indicated that TGT caused a significant inflammatory response in liver endothelial cells at different spatial locations; led to marked inflammatory response, apoptosis and fatty acid metabolism dysfunction in hepatocytes; activated hepatic stellate cells; brought about the activation, inflammation, and phagocytosis of liver capsular macrophages cells; resulted in immune dysfunction of liver lymphocytes; disturbed the intercellular crosstalk in liver microenvironment by regulating various signaling pathways. Thus, these findings elaborate the mechanism underlying TGT-induced acute liver injury, provide new insights into the safe and rational applications in the clinic, and complement the identification of new biomarkers and therapeutic targets for liver protection.

Acute gastrointestinal injury and altered gut microbiota are related to sepsis-induced cholestasis in patients with intra-abdominal infection: a retrospective and prospective observational study

Background

Sepsis-associated liver dysfunction (SALD) has high incidence and mortality in patients with intra-abdominal infection (IAI). The associations between acute gastrointestinal injury (AGI), gut microbiota, and SALD were evaluated in patients with IAI.

Methods

A retrospective study was conducted to assess the relationship between AGI and SALD in patients with IAI. Patients were divided into non-SALD and sepsis-induced cholestasis (SIC) groups, which is a subtype of SALD. SIC was defined as total bilirubin >2 mg/dL. AGI incidences between the two groups were compared using Chi-square test. Subsequently, a prospective study was conducted to investigate the gut microbiota differences between patients without SALD and those with SIC. Fecal samples were collected on days 1, 3, and 7 after admission to analyze changes in gut microbiota using 16S ribosomal ribonucleic acid sequencing.

Results

One hundred thirty-four patients with IAI were included retrospectively, with 77 SALD and 57 non-SALD cases. Among patients with SALD, 71 were diagnosed with SIC. Patients with SIC had a higher incidence of AGI compared to those without SALD (28.07% vs. 56.34%, p < 0.05), and a severity-dependent relationship was found between AGI grade and SIC occurrence. Subsequently, 20 patients with IAI were recruited prospectively, with 10 patients each assigned to the non-SALD and SIC groups. Patients with SIC had a more severe gut microbiota disorder on day 7 than those without SALD, including lower microbiota diversities, decreased abundance of Firmicutes and Bacteroidetes, and increased abundance of Proteobacteria and Actinobacteria at the phylum level. Furthermore, Burkholderia - Caballeronia - Paraburkholderia and Delftia, the two most abundant genera, were significantly higher in the SIC group than in the non-SALD group. Functional prediction analysis showed that the top three KEGG pathways were ribosome, pyrimidine metabolism, and the two-component system. During the first week, the abundance of Proteobacteria decreased significantly, whereas Cyanobacteria increased in the non-SALD group; however, the phyla taxa did not change significantly in the SIC group.

Conclusion

There exists a severity-dependent relationship between AGI grade and SIC occurrence in adult patients with IAI. A severe gut microbiota disorder was discovered in SIC during the first week of the intensive care unit stay.

SIRS, SOFA, qSOFA, and NEWS in the diagnosis of sepsis and prediction of adverse outcomes: a systematic review and meta-analysis

BACKGROUND

We compared Systemic Inflammatory Response Syndrome (SIRS), Sequential Organ Failure Assessment (SOFA), Quick Sepsis-related Organ Failure Assessment (qSOFA), and National Early Warning Score (NEWS) for sepsis diagnosis and adverse outcomes prediction.

METHODS

Clinical studies that used SIRS, SOFA, qSOFA, and NEWS for sepsis diagnosis and prognosis assessment were included. Data were extracted, and meta-analysis was performed for outcome measures, including sepsis diagnosis, in-hospital mortality, 7/10/14-day mortality, 28/30-day mortality, and ICU admission.

RESULTS

Fifty-seven included studies showed good overall quality. Regarding sepsis prediction, SIRS demonstrated high sensitivity (0.85) but low specificity (0.41), qSOFA showed low sensitivity (0.42) but high specificity (0.98), and NEWS exhibited high sensitivity (0.71) and specificity (0.85). For predicting in-hospital mortality, SOFA demonstrated the highest sensitivity (0.89) and specificity (0.69). In terms of predicting 7/10/14-day mortality, SIRS exhibited high sensitivity (0.87), while qSOFA had high specificity (0.75). For predicting 28/30-day mortality, SOFA showed high sensitivity (0.97) but low specificity (0.14), whereas qSOFA displayed low sensitivity (0.41) but high specificity (0.88).

CONCLUSIONS

NEWS independently demonstrates good diagnostic capability for sepsis, especially in high-income countries. SOFA emerges as the optimal choice for predicting in-hospital mortality and can be employed as a screening tool for 28/30-day mortality in low-income countries.

Starvation Protects Hepatocytes from Inflammatory Damage through Paradoxical mTORC1 Signaling

Background and aims: Sepsis-related liver failure is associated with a particularly unfavorable clinical outcome. Calorie restriction is a well-established factor that can increase tissue resilience, protect against liver failure and improve outcome in preclinical models of bacterial sepsis. However, the underlying molecular basis is difficult to investigate in animal studies and remains largely unknown.

METHODS

We have used an immortalized hepatocyte line as a model of the liver parenchyma to uncover the role of caloric restriction in the resilience of hepatocytes to inflammatory cell damage. In addition, we applied genetic and pharmacological approaches to investigate the contribution of the three major intracellular nutrient/energy sensor systems, AMPK, mTORC1 and mTORC2, in this context.

RESULTS

We demonstrate that starvation reliably protects hepatocytes from cellular damage caused by pro-inflammatory cytokines. While the major nutrient- and energy-related signaling pathways AMPK, mTORC2/Akt and mTORC1 responded to caloric restriction as expected, mTORC1 was paradoxically activated by inflammatory stress in starved, energy-deprived hepatocytes. Pharmacological inhibition of mTORC1 or genetic silencing of the mTORC1 scaffold Raptor, but not its mTORC2 counterpart Rictor, abrogated the protective effect of starvation and exacerbated inflammation-induced cell death. Remarkably, mTORC1 activation in starved hepatocytes was uncoupled from the regulation of autophagy, but crucial for sustained protein synthesis in starved resistant cells.

CONCLUSIONS

AMPK engagement and paradoxical mTORC1 activation and signaling mediate protection against pro-inflammatory stress exerted by caloric restriction in hepatocytes.

The gastrointestinal-brain-microbiota axis: a promising therapeutic target for ischemic stroke

Ischemic stroke is a highly complex systemic disease characterized by intricate interactions between the brain and gastrointestinal tract. While our current understanding of these interactions primarily stems from experimental models, their relevance to human stroke outcomes is of considerable interest. After stroke, bidirectional communication between the brain and gastrointestinal tract initiates changes in the gastrointestinal microenvironment. These changes involve the activation of gastrointestinal immunity, disruption of the gastrointestinal barrier, and alterations in gastrointestinal microbiota. Importantly, experimental evidence suggests that these alterations facilitate the migration of gastrointestinal immune cells and cytokines across the damaged blood-brain barrier, ultimately infiltrating the ischemic brain. Although the characterization of these phenomena in humans is still limited, recognizing the significance of the brain-gastrointestinal crosstalk after stroke offers potential avenues for therapeutic intervention. By targeting the mutually reinforcing processes between the brain and gastrointestinal tract, it may be possible to improve the prognosis of ischemic stroke. Further investigation is warranted to elucidate the clinical relevance and translational potential of these findings.

Time-resolved single-cell transcriptomics reveals the landscape and dynamics of hepatic cells in sepsis-induced acute liver dysfunction

Background & Aims

Sepsis-induced acute liver dysfunction often occurs early in sepsis and can exacerbate the pathology by triggering multiple organ dysfunction and increasing lethality. Nevertheless, our understanding of the cellular heterogeneity and dynamic regulation of major nonparenchymal cell lineages remains unclear.

Methods

Here, single-cell RNA sequencing was used to profile multiple nonparenchymal cell subsets and dissect their crosstalk during sepsis-induced acute liver dysfunction in a clinically relevant polymicrobial sepsis model. The transcriptomes of major liver nonparenchymal cells from control and sepsis mice were analysed. The alterations in the endothelial cell and neutrophil subsets that were closely associated with acute liver dysfunction were validated using multiplex immunofluorescence staining. In addition, the therapeutic efficacy of inhibiting activating transcription factor 4 (ATF4) in sepsis and sepsis-induced acute liver dysfunction was explored.

Results

Our results present the dynamic transcriptomic landscape of major nonparenchymal cells at single-cell resolution. We observed significant alterations and heterogeneity in major hepatic nonparenchymal cell subsets during sepsis. Importantly, we identified endothelial cell (CD31⁺Sele⁺Glut1⁺) and neutrophil (Ly6G⁺Lta4h⁺Sort1⁺) subsets that were closely associated with acute liver dysfunction during sepsis progression. Furthermore, we found that ATF4 inhibition alleviated sepsis-induced acute liver dysfunction, prolonging the survival of septic mice.

Conclusions

These results elucidate the potential mechanisms and subsequent therapeutic targets for the prevention and treatment of sepsis-induced acute liver dysfunction and other liver-related diseases.

Impact and Implications

Sepsis-induced acute liver dysfunction often occurs early in sepsis and can lead to the death of the patient. Nevertheless, the pathogenesis of sepsis-induced acute liver dysfunction is not yet clear. We identified the major cell types associated with acute liver dysfunction and explored their interactions during sepsis. In addition, we also found that ATF-4 inhibition could be invoked as a potential therapeutic for sepsis-induced acute liver dysfunction.

Indole-3-propionic acid alleviates sepsis-associated acute liver injury by activating pregnane X receptor

BACKGROUND

The morbidity and mortality of sepsis are extremely high, which is a major problem plaguing human health. However, current drugs and measures for the prevention and treatment of sepsis have little effect. Sepsis-associated acute liver injury (SALI) is an independent risk factor for sepsis, which seriously affects the prognosis of sepsis. Studies have found that gut microbiota is closely related to SALI, and indole-3-propionic Acid (IPA) can activate Pregnane X receptor (PXR). However, the role of IPA and PXR in SALI has not been reported.

METHODS

This study aimed to explore the association between IPA and SALI. The clinical data of SALI patients were collected and IPA level in feces was detected. The sepsis model was established in wild-type mice and PXR knockout mice to investigate the role of IPA and PXR signaling in SALI.

RESULTS

We showed that the level of IPA in patients' feces is closely related to SALI, and the level of IPA in feces has a good ability to identify and diagnose SALI. IPA pretreatment significantly attenuated septic injury and SALI in wild-type mice, but not found in knockout PXR gene mice.

CONCLUSIONS

IPA alleviates SALI by activating PXR, which reveals a new mechanism of SALI, and provides potentially effective drugs and targets for the prevention of SALI.

Pathophysiological role of BACH transcription factors in digestive system diseases

BTB and CNC homologous (BACH) proteins, including BACH1 and BACH2, are transcription factors that are widely expressed in human tissues. BACH proteins form heterodimers with small musculoaponeurotic fibrosarcoma (MAF) proteins to suppress the transcription of target genes. Furthermore, BACH1 promotes the transcription of target genes. BACH proteins regulate physiological processes, such as the differentiation of B cells and T cells, mitochondrial function, and heme homeostasis as well as pathogenesis related to inflammation, oxidative-stress damage caused by drugs, toxicants, or infections; autoimmunity disorders; and cancer angiogenesis, epithelial-mesenchymal transition, chemotherapy resistance, progression, and metabolism. In this review, we discuss the function of BACH proteins in the digestive system, including the liver, gallbladder, esophagus, stomach, small and large intestines, and pancreas. BACH proteins directly target genes or indirectly regulate downstream molecules to promote or inhibit biological phenomena such as inflammation, tumor angiogenesis, and epithelial-mesenchymal transition. BACH proteins are also regulated by proteins, miRNAs, LncRNAs, labile iron, and positive and negative feedback. Additionally, we summarize a list of regulators targeting these proteins. Our review provides a reference for future studies on targeted drugs in digestive diseases.

Dachaihu decoction ameliorates septic intestinal injury via modulating the gut microbiota and glutathione metabolism as revealed by multi-omics

ETHNOPHARMACOLOGICAL RELEVANCE

Dachaihu decoction (DCH), a classic formula for Yangming and Shaoyang Syndrome Complex recorded in "Treatise on Cold Damage", has been widely used in treating intestinal disorders and inflammatory diseases with few side effects in China. However, the mechanism of DCH on septic intestinal injury (SII) remains to be explored.

AIM OF THE STUDY

This study aimed to clarify the mechanism of DCH on SII.

MATERIALS AND METHODS

SII model of rat, established by cecal ligation and puncture (CLP), was used to study the effect of DCH on SII. 24 h mortality was recorded. Histological changes were observed by H&E staining. The expression of tight junction protein ZO-1 (ZO-1) and mucin2 (MUC2) was determined by immunohistochemical analysis. Secretory IgA (sIgA), diamine oxidase (DAO) and intestinal fatty acid binding protein (iFABP) were determined by enzyme-linked immunosorbent assay (ELISA). IL-1β, IL-6 and TNF-α were measured by ELISA and quantitative Real-time PCR (RT-qPCR). The gut microbiota was analyzed by 16S rRNA sequencing. The potential targets and pathways of DCH in treating SII were analyzed by integrative analysis of transcriptomic and metabolomic methods. Total glutathione (T-GSH), GSH, GSSG (reduced form of GSH), GSH peroxidase (GPX), superoxide dismutase (SOD), malonaldehyde (MDA) and indicators of hepatic and renal function were measured by biochemical kits.

RESULTS

Medium dose of DCH improved 24 h mortality of SII rats, reduced the pathological changes of ileum, and increased the expression levels of ZO-1, MUC2 and sIgA. DCH decreased DAO, iFABP of serum and IL-1β, IL-6, TNF-α of ileum. DCH improved α- and β-diversity and modulated the structure of gut microbiota, with Escherichia_Shigella decreased and Bacteroides and Ruminococcus increased. GSH metabolism was identified as the key pathway of DCH on SII by integrative analysis of transcriptome and metabolome. GSH/GSSG and the most common indicators of oxidative stress, were validated. Antioxidative T-GSH, GSH, GPX and SOD were increased, while MDA, the mark of lipid peroxidation was downregulated by DCH. Eventually, DCH was proved to be safe and hepato- and nephro-protective.

CONCLUSION

DCH ameliorated septic intestinal injury possibly by modulating the gut microbiota and enhancing glutathione metabolism of SII rats, without hepatotoxicity and nephrotoxicity.

New challenges in cholangiocarcinoma candidates for elective surgery: harnessing the microbiome dysbiosis

BACKGROUND

The gut microbiota, composed by several species of microorganisms, works to preserve the liver-gut homeostasis and plays an important role during digestion and absorption of nutrients, and in the immune response of the host. In this review, we analyzed the influence of microbiota in patients with cholangiocarcinoma (CCA) who were candidates for elective surgery.

METHODS

A literature review was conducted to identify papers that provided empiric evidence to support that the altered microbiota composition (dysbiosis) is related also to CCA development.

RESULTS

Bacteria such as Helicobacter pylori, Helicobacter hepaticus, and Opisthorchis viverrini increase the risk of CCA. The most abundant genera were Enterococcus, Streptococcus, Bacteroides, Klebsiella, and Pyramidobacter in CCA's biliary microbiota. Additionally, levels of Bacteroides, Geobacillus, Meiothermus, and Anoxybacillus genera were significantly higher. An enrichment of Bifidobacteriaceae, Enterobacteriaceae, and Enterococcaceae families has also been observed in CCA tumor tissue. Microbiota is related to postoperative outcomes in abdominal surgery. The combination of caloric restriction diets in liver cancer or CCA increases the effect of the chemotherapy treatment.

CONCLUSION

The correct use of nutrition for microbiota modulation according to each patient's needs could be a therapeutic tool in combination with elective surgery and chemotherapy to diminish side effects and improve prognosis. Further investigations are needed to fully understand the mechanisms by which they are related.

Chitinase 3 like 1 deficiency ameliorates lipopolysaccharide-induced acute liver injury by inhibition of M2 macrophage polarization

Chitinase 3-like-1 protein (CHI3L1) is involved in various infectious diseases, especially sepsis. Aberrant CHI3L1 expression potentially plays a critical role in chronic inflammation because a considerable number of macrophages are associated with immune/inflammatory diseases. In this study, we examined the effect of CHI3L1 on hepatic sepsis injury using a lipopolysaccharide (LPS)-induced model. LPS-treated CHI3L1 knockout (KO) mice exhibited a higher survival rate than LPS-treated CHI3L1 wild-type (WT) mice. In addition, hepatic injury-related enzyme levels (aspartate transaminase, alanine transaminase, and lactate dehydrogenase) decreased in CHI3L1 KO mice sera, suggesting attenuated LPS-induced septic liver damage in CHI3L1 KO mice. A greater reduction in the mRNA and protein expressions of M2 polarization markers, such as MRC1, ARG1, IL-10, and IL-4, was observed in LPS-induced CHI3L1 KO mice livers than in LPS-induced WT mice livers. Nonetheless, no change in the mRNA and protein expressions of M1 polarization markers, such as INOS, CD86, TNF-α, and IL6, was noted in LPS-induced CHI3L1 KO mice livers compared with those in LPS-induced WT and KO mice. Similar to the in vivo scenario, liver CHI3L1 depletion in LPS-treated HEP3B cells significantly decreased M2 polarization marker protein expression. However, M1 polarization marker protein expression did not differ significantly. These results suggest that CHI3L1 depletion decreases M2 macrophage polarization, and this effect is potentially associated with the alleviation of liver sepsis in CHI3L1 KO mice.

An Overview of Drug Delivery Nanosystems for Sepsis-Related Liver Injury Treatment

Sepsis, which is a systemic inflammatory response syndrome caused by infection, has high morbidity and mortality. Sepsis-related liver injury is one of the manifestations of sepsis-induced multiple organ syndrome. To date, an increasing number of studies have shown that the hepatic inflammatory response, oxidative stress, microcirculation coagulation dysfunction, and bacterial translocation play extremely vital roles in the occurrence and development of sepsis-related liver injury. In the clinic, sepsis-related liver injury is mainly treated by routine empirical methods on the basis of the primary disease. However, these therapies have some shortcomings, such as serious side effects, short duration of drug effects and lack of specificity. The emergence of drug delivery nanosystems can significantly improve drug bioavailability and reduce toxic side effects. In this paper, we reviewed drug delivery nanosystems designed for the treatment of sepsis-related liver injury according to their mechanisms (hepatic inflammation response, oxidative stress, coagulation dysfunction in the microcirculation, and bacterial translocation). Although much promising progress has been achieved, translation into clinical practice is still difficult. To this end, we also discussed the key issues currently facing this field, including immune system rejection and single treatment modalities. Finally, with the rigorous optimization of nanotechnology and the deepening of research, drug delivery nanosystems have great potential for the treatment of sepsis-related liver injury.

Low-Dose Colchicine Attenuates Sepsis-Induced Liver Injury: A Novel Method for Alleviating Systemic Inflammation

Sepsis is a significant public health challenge. The immune system underlies the pathogenesis of the disease. The liver is both an active player and a target organ in sepsis. Targeting the gut immune system using low-dose colchicine is an attractive method for alleviating systemic inflammation in sepsis without inducing immunosuppression. The present study aimed to determine the use of low-dose colchicine in LPS-induced sepsis in mice. C67B mice were injected intraperitoneal with LPS to induce sepsis. The treatment group received 0.02 mg/kg colchicine daily by gavage. Short and extended models were performed, lasting 3 and 5 days, respectively. We followed the mice for biochemical markers of end-organ injury, blood counts, cytokine levels, and liver pathology and conducted proteomic studies on liver samples. Targeting the gut immune system using low-dose colchicine improved mice's well-being measured by the murine sepsis score. Treatment alleviated the liver injury in septic mice, manifested by a significant decrease in their liver enzyme levels, including ALT, AST, and LDH. Treatment exerted a trend to reduce creatinine levels. Low-dose colchicine improved liver pathology, reduced inflammation, and reduced the pro-inflammatory cytokine TNFα and IL1-β levels. A liver proteomic analysis revealed low-dose colchicine down-regulated sepsis-related proteins, alpha-1 antitrypsin, and serine dehydratase. Targeting the gut immune system using low-dose colchicine attenuated liver injury in LPS-induced sepsis, reducing the pro-inflammatory cytokine levels. Low-dose colchicine provides a safe method for immunomodulation for multiple inflammatory disorders.

Fibroblast growth factor 5 overexpression ameliorated lipopolysaccharide-induced apoptosis of hepatocytes through regulation of the phosphoinositide-3-kinase/protein kinase B pathway

BACKGROUND

Sepsis is a systemic inflammatory syndrome induced by several infectious agents. Multiple organs are affected by sepsis, including the liver, which plays an important role in metabolism and immune homeostasis. Fibroblast growth factors (FGFs) participate in several biological processes, although the role of FGF5 in sepsis is unclear.

METHODS

In this study, lipopolysaccharide (LPS) was administrated to mice to establish a sepsis-induced liver injury. A similar in vitro study was conducted using L-02 hepatocytes. Western blot and immunohistochemistry staining were performed to evaluate the FGF5 expression level in liver tissues and cells. Inflammatory cell infiltrations, cleaved-caspase-3 expressions, reactive oxygen species and levels of inflammatory cytokines were detected by immunofluorescence, dihydroethidium staining, and reverse transcription quantitative polymerase chain reaction analysis, respectively. Flow cytometry was used to detect the apoptosis level of cells. In addition, ribonucleic acid (RNA)-sequencing was applied to explore the possible mechanism by which FGF5 exerted effects.

RESULTS

LPS administration caused FGF5 down-regulation in the mouse liver as well as in L-02 hepatocytes. Additionally, with FGF5 overexpression, liver injury and the level of hepatocyte apoptosis were ameliorated. Further, RNA sequencing performed in hepatocytes revealed the phosphoinositide-3-kinase/protein kinase B (PI3K/AKT) pathway as a possible pathway regulated by FGF5 . This was supported using an inhibitor of the PI3K/AKT pathway, which abrogated the protective effect of FGF5 in LPS-induced hepatocyte injury.

CONCLUSION

The anti-apoptotic effect of FGF5 on hepatocytes suffering from LPS has been demonstrated and was dependent on the activation of the PI3K/AKT signaling pathway.

Idebenone reduces sepsis-induced oxidative stress and apoptosis in hepatocytes via RAGE/p38 signaling

Background

Sepsis-induced liver dysfunction is believed to be an independent risk factor for multiple organ dysfunction and death. Idebenone (IDE), a synthetic analog of coenzyme Q10 (CoQ10), possesses an antioxidizing property. The present study aimed to investigate the efficacy of IDE on sepsis-induced liver injury and discuss its reaction mechanism in vivo and in vitro.

Methods

To establish an in vivo model of sepsis-induced liver injury, rats were treated with high-grade cecal ligation and puncture (CLP). Hematoxylin-eosin staining was applied to observe the liver pathological changes, and liver function was examined using alanine aminotransferase (ALT) and aspartate aminotransferase (AST) assay kits. Enzyme-linked immunosorbent assay (ELISA) kits were employed to assess the levels of inflammatory cytokines in serum and tissues. The activities of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were analyzed using MDA, SOD, and GSH-Px assay kits, respectively. The apoptosis of liver tissues was measured by terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) staining, and western blot was employed to estimate apoptosis-related proteins. In vitro, 0.5 μg/mL lipopolysaccharide (LPS) was adopted to administrate primary hepatocytes. The expressions of receptor for advanced glycation end products (RAGE)/p38-related proteins were evaluated by western blot. Cell counting kit-8 (CCK-8) and dichloro-dihydro-fluorescein diacetate (DCFH-DA) assays were utilized to estimate cell viability and reactive oxygen species (ROS) content. Moreover, the transfection efficacy of overexpression (Ov)-RAGE in primary hepatocytes was tested by real-time quantitative polymerase chain reaction (RT-qPCR) and western blot.

Results

IDE could improve liver function and reduce sepsis-induced pathological damage. The levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in the serum and liver tissue of sepsis rats were suppressed by IDE. Additionally, IDE repressed the oxidative stress and apoptosis of liver tissues in sepsis-induced rats. IDE also inhibited RAGE/p38 signaling. Furthermore, IDE revived the decreased viability in LPS-induced hepatocytes concentration-dependently. After overexpressing RAGE, RAGE expression in hepatocytes was significantly elevated. Further functional experiments revealed that IDE attenuated cell viability injury, apoptosis, oxidative stress, and inflammatory damage in LPS-induced hepatocytes via RAGE/p38 signaling.

Conclusions

IDE helped to protect against sepsis-induced liver injury via the regulation of RAGE/p38 signaling.

Urine metabolomics and microbiome analyses reveal the mechanism of anti-tuberculosis drug-induced liver injury, as assessed for causality using the updated RUCAM: A prospective study

Background

Anti-tuberculosis drug-induced liver injury (ATB-DILI) is one of the most common adverse reactions that brings great difficulties to the treatment of tuberculosis. Thus, early identification of individuals at risk for ATB-DILI is urgent. We conducted a prospective cohort study to analyze the urinary metabolic and microbial profiles of patients with ATB-DILI before drug administration. And machine learning method was used to perform prediction model for ATB-DILI based on metabolomics, microbiome and clinical data.

Methods

A total of 74 new TB patients treated with standard first-line anti-TB treatment regimens were enrolled from West China Hospital of Sichuan University. Only patients with an updated RUCAM score of 6 or more were accepted in this study. Nontargeted metabolomics and microbiome analyses were performed on urine samples prior to anti-tuberculosis drug ingestion to screen the differential metabolites and microbes between the ATB-DILI group and the non-ATB-DILI group. Integrating electronic medical records, metabolomics, and microbiome data, four machine learning methods was used, including random forest algorithm, artificial neural network, support vector machine with the linear kernel and radial basis function kernel.

Results

Of all included patients, 69 patients completed follow-up, with 16 (23.19%) patients developing ATB-DILI after antituberculosis treatment. Finally, 14 ATB-DILI patients and 30 age- and sex-matched non-ATB-DILI patients were subjected to urinary metabolomic and microbiome analysis. A total of 28 major differential metabolites were screened out, involving bile secretion, nicotinate and nicotinamide metabolism, tryptophan metabolism, ABC transporters, etc. Negativicoccus and Actinotignum were upregulated in the ATB-DILI group. Multivariate analysis also showed significant metabolic and microbial differences between the non-ATB-DILI and severe ATB-DILI groups. Finally, the four models showed high accuracy in predicting ATB-DILI, with the area under the curve of more than 0.85 for the training set and 1 for the validation set.

Conclusion

This study characterized the metabolic and microbial profile of ATB-DILI risk individuals before drug ingestion for the first time. Metabolomic and microbiome characteristics in patient urine before anti-tuberculosis drug ingestion may predict the risk of liver injury after ingesting anti-tuberculosis drugs. Machine learning algorithms provides a new way to predict the occurrence of ATB-DILI among tuberculosis patients.

Bioinformatics Analysis Identifies TNFRSF1A as a Biomarker of Liver Injury in Sepsis TNFRSF1A is a Biomarker for Septic Liver Injury

Sepsis is a severe disease with high mortality, and liver injury is an independent risk factor for sepsis morbidity and mortality. We analyzed co-differentially expressed genes (co-DEGs) to explore potential biomarkers and therapeutic targets for sepsis-related liver injury. Three gene expression datasets (GSE60088, GSE23767, and GSE71530) were downloaded from the Gene Expression Omnibus (GEO). DEGs were screened between sepsis and control samples using GEO2R. The association of these DEGs with infection and liver disease was analyzed by using the CTD database. GO functional analysis, KEGG pathway enrichment analysis, and protein-protein interaction (PPI) network analysis were performed to elucidate the potential molecular mechanism of DEGs. DEGs of different tissues in GSE60088 were analyzed again to obtain specific markers of septic liver injury. Mouse model of sepsis was also established by cecal ligation and puncture (CLP), and the expression of specific markers in liver, lung, and kidney tissues was analyzed using Western blot. Here, we identified 21 DEGs in three datasets with 8 hub genes, all of which showed higher inference scores in liver diseases than bacterial infections. Among them, only TNFRSF1A had a liver-specific differential expression. TNFRSF1A was also confirmed to be specifically reduced in septic liver tissues in mice. Therefore, TNFRSF1A may serve as a potential biomarker for septic liver injury.