The Role of Monocytes and Macrophages in Acute and Acute-on-Chronic Liver Failure

Ancient Herbal Formula Mahuang Lianqiao Chixiaodou Decoction Protects Acute and Acute-on-Chronic Liver Failure via Inhibiting von Willebrand Factor Signaling

BACKGROUND

Acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) are characterized by systemic inflammation and high mortality, but there is no effective clinical treatment. As a classic traditional Chinese medicine (TCM) formula, MaHuang-LianQiao-ChiXiaoDou decoction (MHLQD) has been used clinically for centuries to treat liver diseases.

METHODS

The LPS/D-GalN-induced ALF mice model and the CCl4+LPS/D-GalN-induced ACLF mice model were used to observe the therapeutic effects of MHLQD on mice mortality, hepatocytes death, liver injury, and immune responses.

RESULTS

MHLQD treatment significantly improved mice mortality. Liver injury and systemic and hepatic immune responses were also ameliorated after MHLQD treatment. Mechanistically, proteomic changes in MHLQD-treated liver tissues were analyzed and the result showed that the thrombogenic von Willebrand factor (VWF) was significantly inhibited in MHLQD-treated ALF and ACLF models. Histological staining and western blotting confirmed that VWF/RAP1B/ITGB3 signaling was suppressed in MHLQD-treated ALF and ACLF models. Furthermore, mice treated with the VWF inhibitor ADAMTS13 showed a reduced therapeutic effect from MHLQD treatment.

CONCLUSIONS

Our study indicated that MHLQD is an effective herbal formula for the treatment of ALF and ACLF, which might be attributed to the protection of hepatocytes from death via VWF/RAP1B/ITGB3 signaling.

Spotlight on liver macrophages for halting liver disease progression and injury

INTRODUCTION

Over the past two decades, understanding of hepatic macrophage biology has provided astounding details of their role in the progression and regression of liver diseases. The hepatic macrophages constitute resident macrophages, Kupffer cells, and circulating bone marrow monocyte-derived macrophages, which play a diverse role in liver injury and repair. Imbalance in the macrophage population leads to pathological consequences and is responsible for the initiation and progression of acute and chronic liver injuries. Further, distinct populations of hepatic macrophages and their high heterogeneity make their complex role enigmatic. The unique features of distinct phenotypes of macrophages have provided novel biomarkers for defining the stages of liver diseases. The distinct mechanisms of hepatic macrophages polarization and recruitment have been at the fore front of research. In addition, the secretome of hepatic macrophages and their immune regulation has provided clinically relevant therapeutic targets.

AREAS COVERED

Herein we have highlighted the current understanding in the area of hepatic macrophages, and their role in the progression of liver injury.

EXPERT OPINION

It is essential to ascertain the physiological and pathological role of evolutionarily conserved distinct macrophage phenotypes in different liver diseases before viable approaches may see a clinical translation.

Identification of effective diagnostic biomarker and immune cell infiltration characteristics in acute liver failure by integrating bioinformatics analysis and machine-learning strategies

Background: To determine effective biomarkers for the diagnosis of acute liver failure (ALF) and explore the characteristics of the immune cell infiltration of ALF.

Methods: We analyzed the differentially expressed genes (DEGs) between ALF and control samples in GSE38941, GSE62029, GSE96851, GSE120652, and merged datasets. Co-expressed DEGs (co-DEGs) identified from the five datasets were analyzed for enrichment analysis. We further constructed a PPI network of co-DEGs using the STRING database. Then, we integrated the two kinds of machine-learning strategies to identify diagnostic biomarkers of top hub genes screened based on MCC and Degree methods. And the potential diagnostic performance of the biomarkers for ALF was estimated using the AUC values. Data from GSE14668, GSE74000, and GSE96851 databases was performed as external verification sets to validate the expression level of potential diagnostic biomarkers. Furthermore, we analyzed the difference in the protein level of diagnostic biomarkers between normal and ALF mice models. Finally, we used CIBERSORT to estimate relative infiltration levels of 22 immune cell subsets in ALF samples and further analyzed the relationships between the diagnostic biomarkers and infiltrated immune cells.

Results: A total of 200 co-DEGs were screened. Enrichment analyses depicted that they are highly enriched in metabolism and matrix collagen production-associated processes. The top 28 hub genes were obtained by integrating MCC and Degree methods. Then, the collagen type IV alpha 2 chain (COL4A2) was regarded as the diagnostic biomarker and showed excellent specificity and sensitivity. COL4A2 also showed a statistically significant difference and excellent diagnostic effectiveness in the verification set. In addition, there was a significant upregulation in the COL4A2 protein level in ALF mice models compared with the normal group. CIBERSORT analysis showed that activated CD4 T cells, plasma cells, macrophages, and monocytes may be implicated in the progress of ALF. In addition, COL4A2 showed different degrees of correlation with immune cells.

Conclusion: In conclusion, COL4A2 may be a diagnostic biomarker for ALF, and immune cell infiltration may have important implications for the occurrence and progression of ALF.

Combinatorial targeting of G-protein-coupled bile acid receptor 1 and cysteinyl leukotriene receptor 1 reveals a mechanistic role for bile acids and leukotrienes in drug-induced liver injury

BACKGROUND AND AIM

Drug-induced liver injury (DILI) is a common disorder that involves both direct liver cell toxicity and immune activation. The bile acid receptor, G-protein-coupled bile acid receptor 1 (GPBAR1; Takeda G-protein-coupled receptor 5 [TGR5]), and cysteinyl leukotriene receptor (CYSLTR) 1 are G-protein-coupled receptors activated by bile acids and leukotrienes, exerting opposite effects on cell-to-cell adhesion, inflammation, and immune cell activation. To investigate whether GPBAR1 and CYSLTR1 mutually interact in the development of DILI, we developed an orally active small molecule, CHIN117, that functions as a GPBAR1 agonist and CYSLTR1 antagonist.

APPROACH AND RESULTS

RNA-sequencing analysis of liver explants showed that acetaminophen (APAP) intoxication positively modulates the leukotriene pathway, CYSLTR1, 5-lipoxygenase, and 5-lipoxygenase activating protein, whereas GPBAR1 gene expression was unchanged. In mice, acute liver injury induced by orally dosing APAP (500 mg/kg) was severely exacerbated by Gpbar1 gene ablation and attenuated by anti-Cysltr1 small interfering RNA pretreatment. Therapeutic dosing of wild-type mice with CHIN117 reversed the liver damage caused by APAP and modulated up to 1300 genes, including 38 chemokines and receptors, that were not shared by dosing mice with a selective GPBAR1 agonist or CYSLTR1 antagonist. Coexpression of the two receptors was detected in liver sinusoidal endothelial cells (LSECs), monocytes, and Kupffer cells, whereas combinatorial modulation of CYSLTR1 and GPBAR1 potently reversed LSEC/monocyte interactions. CHIN117 reversed liver damage and liver fibrosis in mice administered CCl₄ .

CONCLUSIONS

By genetic and pharmacological approaches, we demonstrated that GPBAR1 and CYSLTR1 mutually interact in the development of DILI. A combinatorial approach designed to activate GPBAR1 while inhibiting CYSLTR1 reverses liver injury in models of DILI.

Lipopolysaccharide Inhibits Autophagy and Promotes Inflammatory Responses via p38 MAPK-Induced Proteasomal Degradation of Atg13 in Hepatic Stellate Cells

Background

Inflammation plays a critical role in the progression of acute-on-chronic liver failure (ACLF). Atg13 is a vital regulatory component of the ULK1 complex, which plays an essential role in the initiation of autophagy. Previously, hepatic stellate cells (HSCs) were considered to be noninflammatory cells that contribute only to hepatic fibrosis. Recently, it has been found that HSCs can secrete inflammatory cytokines and participate in hepatic inflammation. Autophagy and proteasome-mediated degradation constitute two major means of protein turnover in cells. Autophagy has been shown to regulate inflammation, but it is unclear whether ubiquitin (Ub)-proteasome system (UPS) is involved in inflammatory responses in HSCs during ACLF.

Methods

Clinical data were collected from ACLF patients, and surgically resected paraffin-embedded human ACLF liver tissue specimens were collected. The expression of Atg13 was assessed by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Secretion of IL-1β was assessed by ELISA. Atg13 was knocked down by siRNA in LX2 cells. Coimmunoprecipitation assay was used to detect protein binding and polyubiquitination of Atg13. In vitro tests with LX2 cells were performed to explore the effects and regulation of p38 MAPK, Atg13, UPS, autophagy, and inflammation.

Results

Serum lipopolysaccharide (LPS) was positively associated with disease severity in ACLF patients, and p38 MAPK was overexpressed in ACLF liver tissue. We evaluated the role of Atg13 in HSC inflammation and explored the possible underlying mechanisms. Inflammatory factors were upregulated via activation of p38 MAPK and inhibition of autophagy in LX-2 cells. Expression of Atg13 was decreased in LPS-incubated LX2 cells. Atg13 knockdown markedly inhibited autophagy and promoted LPS-induced inflammation in LX2 cells. Our in vitro experiments also showed that LPS induced depletion of Atg13 via UPS, and this process was dependent on p38 MAPK.

Conclusions

LPS induces proteasomal degradation of Atg13 via p38 MAPK, thereby participating in the aggravation of LPS-induced autophagy inhibition and inflammatory responses in LX2 cells. Atg13 serves as a mediator between autophagy and proteasome. Modulation of Atg13 or proteasome activity might be a novel strategy for treating HSC inflammation.

Low Baseline but Not Delta Cortisol Relates to 28-Day Transplant-Free Survival in Acute and Acute-on-Chronic Liver Failure

Background and Aims

The clinical, prognostic, and therapeutic impact of adrenal insufficiency in acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) remains controversial and exact diagnostic criteria are lacking. We sought to determine the diagnostic and therapeutic value of cortisol measurement and glucocorticoid (GC) treatment in ALF and ACLF.

Methods

28-day transplant-free survival (TFS) was studied in relation to absolute cortisol concentrations and to GC treatment in ALF (n = 30) and ACLF (n = 34) patients. Cortisol concentrations and short synacthen test were assessed by chemiluminescence immunoassay and liquid chromatography-mass spectrometry. Clinicians decided independently on GC treatment. In relation, phenotypic and functional characteristics of circulating monocytes were assessed.

Results

In ALF, baseline cortisol concentrations <387 nmol/L predicted TFS (sensitivity 83%, specificity 53%). In ACLF, baseline cortisol <392 nmol/L correlated with TFS (sensitivity 80%, specificity 61%). In both, ALF and ACLF, GC treatment did not influence 28-day TFS in patients with low baseline cortisol. However, in patients with baseline cortisol exceeding 387 and 392 nmol/L, respectively, TFS was higher if they had been treated with GC. High baseline cortisol was associated with low HLA-DR expression on monocytes.

Conclusion

Our data suggest a prognostic value of baseline cortisol measurement in ALF and ACLF. Overall, strong activation of the hypothalamic-pituitary-adrenal axis indicated poor prognosis. Furthermore, baseline cortisol deserves prospective evaluation as a guide for GC treatment decision-making.

Pluripotent Stem Cell-derived Strategies to Treat Acute Liver Failure: Current Status and Future Directions

Liver disease has long been a heavy health and economic burden worldwide. Once the disease is out of control and progresses to end-stage or acute organ failure, orthotopic liver transplantation (OLT) is the only therapeutic alternative, and it requires appropriate donors and aggressive administration of immunosuppressive drugs. Therefore, hepatocyte transplantation (HT) and bioartificial livers (BALs) have been proposed as effective treatments for acute liver failure (ALF) in clinics. Although human primary hepatocytes (PHs) are an ideal cell source to support these methods, the large demand and superior viability of PH is needed, which restrains its wide usage. Thus, a finding alternative to meet the quantity and quality of hepatocytes is urgent. In this context, human pluripotent stem cells (PSC), which have unlimited proliferative and differential potential, derived hepatocytes are a promising renewable cell source. Recent studies of the differentiation of PSC into hepatocytes has provided evidence that supports their clinical application. In this review, we discuss the recent status and future directions of the potential use of PSC-derived hepatocytes in treating ALF. We also discuss opportunities and challenges of how to promote such strategies in the common applications in clinical treatments.

Bioinformatics analyses of potential ACLF biological mechanisms and identification of immune-related hub genes and vital miRNAs

Acute-on-chronic liver failure (ACLF) is a critical and refractory disease and a hepatic disorder accompanied by immune dysfunction. Thus, it is essential to explore key immune-related genes of ACLF and investigate its mechanisms. We used two public datasets (GSE142255 and GSE168048) to perform various bioinformatics analyses, including WGCNA, CIBERSORT, and GSEA. We also constructed an ACLF immune-related protein-protein interaction (PPI) network to obtain hub differentially expressed genes (DEGs) and predict corresponding miRNAs. Finally, an ACLF rat model was established to verify the results. A total of 388 DEGs were identified in ACLF, including 162 upregulated and 226 downregulated genes. The enrichment analyses revealed that these DEGs were mainly involved in inflammatory-immune responses and biosynthetic metabolic pathways. Twenty-eight gene modules were obtained using WGCNA and the coral1 and darkseagreen4 modules were highly correlated with M1 macrophage polarization. As a result, 10 hub genes and 2 miRNAs were identified to be significantly altered in ACLF. The bioinformatics analyses of the two datasets presented valuable insights into the pathogenesis and screening of hub genes of ACLF. These results might contribute to a better understanding of the potential molecular mechanisms of ACLF. Finally, further studies are required to validate our current findings.

Susceptibility to Infections During Acute Liver Injury Depends on Transient Disruption of Liver Macrophage Niche

Kupffer cells are the primary liver resident immune cell responsible for the liver firewall function, including clearance of bacterial infection from the circulation, as they are strategically positioned inside the liver sinusoid with intimate contact with the blood. Disruption in the tissue-resident macrophage niche, such as in Kupffer cells, can lead to a window of susceptibility to systemic infections, which represents a significant cause of mortality in patients with acetaminophen (APAP) overdose-induced acute liver injury (ALI). However, how Kupffer cell niche disruption increases susceptibility to systemic infections in ALI is not fully understood. Using a mouse model of ALI induced by APAP overdose, we found that Kupffer cells upregulated the apoptotic cell death program and were markedly reduced in the necrotic areas during the early stages of ALI, opening the niche for the infiltration of neutrophils and monocyte subsets. In addition, during the resolution phase of ALI, the remaining tissue macrophages with a Kupffer cell morphology were observed forming replicating cell clusters closer to necrotic areas devoid of Kupffer cells. Interestingly, mice with APAP-induced liver injury were still susceptible to infections despite the dual cellular input of circulating monocytes and proliferation of remaining Kupffer cells in the damaged liver. Therapy with bone marrow-derived macrophages (BMDM) was shown to be effective in occupying the niche devoid of Kupffer cells following APAP-induced ALI. The rapid BMDM migration to the liver and their positioning within necrotic areas enhanced the healing of the tissue and restored the liver firewall function after BMDM therapy. Therefore, we showed that disruption in the Kupffer cell niche and its impaired function during acute liver injury are key factors for the susceptibility to systemic bacterial infections. In addition, modulation of the liver macrophage niche was shown to be a promising therapeutic strategy for liver injuries that reduce the Kupffer cell number and compromise the organ function.

An improved method for isolation and flow cytometric characterization of intrahepatic leukocytes from fatty and fibrotic liver tissues

Flow cytometry is an imperative tool to characterize alterations in a wide range of immune cell populations during inflammatory conditions and disease states that affect the liver such as the obesity-induced non-alcoholic fatty liver disease and liver fibrosis. Identification and quantification of immune cell subsets from the liver is critically dependent on efficient isolation of intrahepatic leukocytes. The isolation of leukocytes from fatty and fibrotic livers and processing the cells for flow cytometry can be challenging with respect to cell yields, purity and most importantly, the level of autofluorescence resulting from fat deposition. Here, we describe an efficient method for isolating intrahepatic leukocytes from mice fed with high fat diet and propose a strategy to alleviate autofluorescence during phenotyping by multicolor flowcytometry. We also describe a gating strategy for robust identification of granulocytes, pro-inflammatory, anti-inflammatory and transitional state monocyte subsets, dendritic cells, B cell, T lymphocyte subpopulations and NK cell subsets. Overall, the procedures described here will allow simultaneous processing of several samples while ensuring reproducible cell isolation and efficient noise reduction required for reliable characterization of intrahepatic leukocytes from the fatty liver tissues.

Identification of key genes and infiltrating immune cells among acetaminophen-induced acute liver failure and HBV-associated acute liver failure

BACKGROUND

Acute liver failure (ALF) is a life-threatening complication that is relatively uncommon. ALF causes severe hepatocyte damage and necrosis, which can lead to liver dysfunction and even multi-organ failure. A growing body of evidence suggests that immune cell infiltration and some abnormally expressed genes are associated with ALF development. However, in ALF, they have yet to be thoroughly investigated.

METHODS

The Gene Expression Omnibus (GEO) database was used to obtain microarray datasets such as GSE74000, GSE120652, GSE38941, and GSE14668, which were then examined via GEO2R to determine differentially expressed genes (DEGs) associated with ALF. Metascape was employed to annotate the underlined genes using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The mechanism of IGF1 in 2 different kinds of ALF including acetaminophen-induced ALF and hepatitis B virus (HBV)-induced ALF was studied using gene set enrichment analysis (GSEA). Next, immune cell infiltration was investigated and differentiated in ALF using CIBERSORT.

RESULTS

Six genes (HAO2, IGF1, PLA2G7, SC5D, GNE, SLC1A1) were found to be abnormally expressed in the 2 distinct types of ALF i.e., acetaminophen-induced ALF and HBV-induced ALF. IGF1 was identified as a hub gene in ALF and was found to be associated with several developmental cascades including immune responses, inflammatory responses, and intracellular calcium homeostasis. Additionally, the number of CD4 naive T cells, CD8 T cells, and follicular helper T cells was increased in acetaminophen-induced ALF, whereas the number of activated NK cells, resting NK cells, and plasma cells was increased in HBV-induced ALF.

CONCLUSIONS

The present study determined a potential molecular target, namely IGF1, in acetaminophen-induced ALF and HBV-induced ALF, which may provide novel insights into the pathophysiology and management of ALF. Concurrently, the putative immunological pathways have been found.

A Clinical Diagnostic Study: Fibulin-2 is a Novel Promising Biomarker for Predicting Infection

INTRODUCTION

Infection remains a major cause of morbidity and mortality in hospital. As uncontrolled early infection may develop into systemic infection and eventually progress to sepsis, it is important to address infection at an early stage. Furthermore, early detection and prompt diagnosis of infection are the basis of clinical intervention. However, as a result of the interference of complex aetiologies, including fever and trauma, problems regarding the sensitivity and specificity of current diagnostic indices remain, such as for C-reactive protein (CRP), procalcitonin (PCT), white blood cells (WBC), neutrophil ratio (NEU%), interleukin-6 (IL-6) and D-dimer. As a result, there is an urgent need to develop new biomarkers to diagnose infection.

METHODS

From January to October 2021, consecutive patients in the emergency department (ED) were recruited to investigate the feasibility of fibulin-2 as a diagnostic indicator of early infection. Fibulin-2 concentrations in plasma were determined with enzyme-linked immunosorbent assay (ELISA). The performance of fibulin-2 for predicting infection was analysed by receiver operating characteristic (ROC) curves.

RESULTS

We found that the plasma fibulin-2 level was elevated in patients with infection compared with those without infection. ROC curve analysis showed that the area under the curve (AUC) for fibulin-2 was 0.712. For all patients included, the diagnostic ability of fibulin-2 (AUC 0.712) performed as well as CRP (AUC 0.667) and PCT (AUC 0.632), and better than WBC (AUC 0.620), NEU% (AUC 0.619), IL-6 (AUC 0.561) and D-dimer (AUC 0.630). In patients with fever, fibulin-2 performed as well as PCT and better than the other biomarkers in infection diagnosis. In particular, fibulin-2 performed better than all these biomarkers in patients with trauma.

CONCLUSION

Fibulin-2 is a novel promising diagnostic biomarker for predicting infection.

Why nanoparticles prefer liver macrophage cell uptake in vivo

Effective delivery of therapeutic and diagnostic nanoparticles is dependent on their ability to accumulate in diseased tissues. However, most nanoparticles end up in liver macrophages regardless of nanoparticle design after administration. In this review, we describe the interactions of liver macrophages with nanoparticles. Liver macrophages have significant advantages in interacting with circulating nanoparticles over most target cells and tissues in the body. We describe these advantages in this article. Understanding these advantages will enable the development of strategies to overcome liver macrophages and deliver nanoparticles to targeted diseased tissues effectively. Ultimately, these approaches will increase the therapeutic efficacy and diagnostic signal of nanoparticles.

Noncanonical Wnt5a/JNK Signaling Contributes to the Development of D-Gal/LPS-Induced Acute Liver Failure

Acute liver failure (ALF) is a deadly clinical disorder with few effective treatments and unclear pathogenesis. In our previous study, we demonstrated that aberrant Wnt5a expression was involved in acute-on-chronic liver failure. However, the role of Wnt5a in ALF is unknown. We investigated the expression of Wnt5a and its downstream c-Jun N-terminal kinase (JNK) signaling in a mouse model of ALF established by coinjection of D-galactosamine (D-Gal) and lipopolysaccharide (LPS) in C57BL/6 mice. We also investigated the role of Box5, a Wnt5a antagonist, in vivo. Moreover, the effect of Wnt5a/JNK signaling on downstream inflammatory cytokine expression, phagocytosis, and migration in THP-1 macrophages was studied in vitro. Aberrant Wnt5a expression and JNK activation were detected in D-Gal/LPS-induced ALF mice. Box5 pretreatment reversed JNK activation and eventually decreased the mortality rate of D-Gal/LPS-treated mice, with reduced hepatic necrosis and apoptosis, serum ALT and AST levels, and liver inflammatory cytokine expression, although the latter was not significant. We further demonstrated that recombinant Wnt5a (rWnt5a)-induced tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) mRNA expression and increased THP-1 macrophage phagocytosis in a JNK-dependent manner, which could be restored by Box5. In addition, rWnt5a-induced migration of THP-1 macrophages was also reversed by Box5. Our findings suggested that Wnt5a/JNK signaling plays an important role in the development of ALF and that Box5 could have particular hepatoprotective effects in ALF.

Single-Cell RNA Transcriptomics Reveals the State of Hepatic Lymphatic Endothelial Cells in Hepatitis B Virus-Related Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is an acutely decompensated cirrhosis syndrome with high short-term mortality. Very little is known about the relationship between the lymphatic system and ACLF. We explored the role of hepatic lymphatic vessels (LVs) and lymphatic endothelial cells (LyECs) in ACLF using human liver samples with the help of single-cell RNA-sequencing (scRNA-seq) technology. Here, ACLF exhibited more severe liver injury and inflammation than cirrhosis, as indicated by significant increases in plasma levels of alanine/aspartate aminotransferases and total bilirubin. Compared with cirrhosis cases, the number of intrahepatic LVs was decreased significantly in ACLF patients. ScRNA-seq revealed that many monocyte/macrophages infiltrated into the liver of ACLF cases. Meanwhile, scRNA-seq revealed a group of apoptotic and dysfunctional LyECs, which were the result of secreted phosphoprotein 1 (SPP1) released from infiltrating monocyte/macrophages. In vitro, SPP1 increased the proportion of dead LyECs significantly and impaired the ability of tube formation of LyECs in a dose- and time-dependent manner. In conclusion, ACLF is associated with less LV and LyEC dysfunction, at least in part mediated by SPP1 released from infiltrating monocyte/macrophages. Hepatic LVs and LyECs can be a novel therapeutic strategy for ACLF.

Granulocyte Colony-Stimulating Factor Accelerates the Recovery of Hepatitis B Virus-Related Acute-on-Chronic Liver Failure by Promoting M2-Like Transition of Monocytes

BACKGROUND AND AIM

Acute-on-chronic liver failure (ACLF) has a high mortality rate. The role of granulocyte colony-stimulating factor (G-CSF) in ACLF remains controversial. Monocytes/macrophages are core immune cells, which are involved in the initiation and progression of liver failure; however, the effect of G-CSF on monocytes/macrophages is unclear. The study aimed to verify the clinical efficacy of G-CSF and explore the effect of it on monocytes in hepatitis B virus (HBV)-related ACLF (HBV-ACLF) paitents.

METHODS

We performed a large randomized controlled clinical trial for the treatment of HBV-ACLF using G-CSF. A total of 111 patients with HBV-ACLF were prospectively randomized into the G-CSF group (5 μg/kg G-CSF every day for 6 days, then every other day until day 18) or the control group (standard therapy). All participants were followed up for at least 180 days. The relationship between monocyte count and mortality risk was analyzed. The effect of G-CSF on the phenotype and function of monocytes from patients with HBV-ACLF was evaluated using flow cytometry in vivo and in vitro experiments.

RESULTS

The survival probability of the G-CSF group at 180 days was higher than that of the control group (72.2% vs. 53.8%, P = 0.0142). In the G-CSF-treated group, the monocyte counts on days 0 and 7 were independently associated with an evaluated mortality risk in the fully adjusted model (Model 3) [at day 0: hazard ratio (HR) 95% confidence interval (CI): 15.48 (3.60, 66.66), P = 0.0002; at day 7: HR (95% CI): 1.10 (0.50, 2.43), P=0.8080]. Further analysis showed that after treatment with G-CSF in HBV-ACLF patients, the expression of M1-like markers (HLA-DR and CD86) in monocytes decreased (HLA-DR: P = 0.0148; CD86: P = 0.0764). The expression of MerTK (M2-like marker) increased (P = 0.0002). The secretion of TNF-α, IL-6, and IL-10 from monocytes decreased without lipopolysaccharide (LPS) stimulation (TNF-α: P < 0.0001; IL-6: P= 0.0025; IL-10: P = 0.0004) or with LPS stimulation (TNF-α: P = 0.0439; P = 0.0611; IL-10: P = 0.0099). Similar effects were observed in vitro experiments.

CONCLUSION

G-CSF therapy confers a survival benefit to patients with HBV-ACLF. G-CSF can promote the anti-inflammatory/pro-restorative phenotype (M2-like) transition of monocytes, which may contribute to the recovery of ACLF.Clinical Trial Registration Number: ClinicalTrials.gov, identifier (NCT02331745).

Chinese Herb Jiedu Huayu Granules Inhibiting Immune and Inflammatory Response of Rats with Acute Liver Failure by Regulating the NF-κB Signaling Pathway

Objective

To research the influence of Chinese medicine Jiedu Huayu granules (JDHY) on the immune response and inflammatory response of rats with acute liver failure (ALF) and investigate its related mechanism.

Methods

Rats were randomly divided into 4 groups: control group (n = 6) were injected with the same amount of normal saline; ALF group (n = 10) were injected intraperitoneally with D-GaIN (700 mg/kg) and LPS (10 μg/kg); ALF+JDHY group (n = 10) were given JDHY 57.55 g/kg/d by gavage for 7 days and injected intraperitoneally with D-GaIN/LPS after the last dose; and ALF+BAY group (n = 10) were given BAY 10 mg/kg/d by gavage for 7 days and injected intraperitoneally with D-GaIN/LPS after the last dose. Changes in liver function and coagulation function were examined in rat serum; the pathological varieties of liver tissues were verified by HE staining; immunohistochemistry was utilized to determine the ratio of PCNA and F4/80 in liver tissues; the flow cytometry was applied to determine the ratio of CD4+/CD8+ cells in peripheral blood mononuclear cells (PBMCs); ELISA and qRT-PCR were utilized to check the level of IL-10, IL-6, IL-13, IL-1β, TNF-α, IFN-γ, and CD163 in serum and liver cells. Western blot was adopted to check the expression of apoptotic protein and expression and NF-κB pathway-related protein expression.

Results

JDHY and BAY could decline the expression of AST, ALT, ALP, and TBiL in ALF rat serum significantly (P < 0.01), increase PTA and PLT (P < 0.01), and mitigate liver tissue damage. Besides, JDHY and BAY could reduce the apoptosis and improve the proliferation of the liver cells in rats with ALF; meanwhile, the ratio of CD4+ cells and F4/80 cells was reduced while CD8+ cells were increased (P < 0.01). Further, JDHY and BAY could reduce the level of IFN-γ, IL-6, IL-1β, and TNF-α while increasing the level of IL-10 and IL-13 (P < 0.01). Additionally, the expression of sCD163 in serum and CD163 expression in liver tissues increased (P < 0.01). The result of western blot confirmed that JDHY could inhibit the phosphorylated expression of NF-κB, IKβα, and IKKβ in the ALF rat tissues.

Conclusions

JDHY can upregulate the level of CD163/sCD163 by the NF-κB signaling pathway, thereby regulating immune response, inhibiting inflammatory response, and ultimately improving ALF in the rats.

Clinical Implication of Plasma CD163 in Patients With Acute-on-Chronic Liver Failure

BACKGROUND

It was postulated that CD163 plasma level should be incorporated into existing predictive systems to improve prognostic performance in patients with acute-on-chronic liver failure (ACLF).

PATIENTS AND METHODS

Plasma CD163 was assessed in 24 consecutive patients with ACLF (17 male, 7 female; mean age 54.9 years; 50% with alcohol-related liver disease) and compered with the existing scoring tools to predict the availability of transplantation or survival without liver transplant (LT).

RESULTS

There were no differences in plasma CD163 levels between graft recipients and deceased patients on the waiting list or transplant survivors vs nonsurvivors. CD163 did not correlate with CLIF-ACLF, CLIF Consortium organ failure score (CLIF-OF), and ACLF grades (all P < .05). However, sequential organ failure assessment (SOFA), CLIF Consortium acute-on-chronic liver failure score (CLIF-C) ACLF, and CLIF-C OF scores correlated significantly with mortality (P < .01) in contrast to Child-Pugh scale and Model for End-Stage Liver Disease score (all P > .05). Transplanted survivors and deceased individuals differed robustly with respect to the SOFA and CLIF-SOFA scores and the CLIF-C OF, CLIF-C Grade, and CLIF-C ACLF scales (all P < .05). CLIF-C performed well in ACLF prognostication with an area under receiver operating characteristic curve (AUROC) 0.893 (95% CI, 0.766-1), surpassing in that respect CD163 with AUROC of 0.664 (95% CI, 0417-0.911).

CONCLUSIONS

Our preliminary results showed that the plasma CD163 level in patients with ACLF played only a minor role in predicting LT futility/benefit, with no impact on the narrow transplant window. Moreover, to optimize LT outcomes, newly developed CLIF-C scales showed superior predictive value.

Mesenchymal stem cell treatment restores liver macrophages homeostasis to alleviate mouse acute liver injury revealed by single-cell analysis

Acute liver injury (ALI) is characterized by massive hepatocyte necrosis and subsequent recruitment of myeloid cells to liver. Mesenchymal stem cells (MSCs) have therapeutic potential for ALI through their immunoregulation on macrophages, but the mechanism is not completely clear due to the heterogeneity and controversy of liver macrophages. Here, we detected the survival rate, biochemical indexes, histopathology, and inflammatory chemokine levels to assess the efficacy of MSC treatment on CCl4-induced ALI of C57BL/6 mice. Furthermore, flow cytometry and single-cell RNA sequencing (scRNA-Seq) were used to precisely distinguish macrophage populations and reveal the immunoregulation of MSCs. MSC treatment could effectively alleviate ALI and mitigate the recruitment of mononuclear phagocytes. Flow cytometry and scRNA-Seq analyses collectively indicated that there were monocytes with high Ly6C expression and heterogeneous monocyte-derived macrophages (MoMF) with low Ly6C expression in liver. Ly6Chi pro-inflammatory monocytes and Ly6Clo MoMF with powerful phagocytosis dominated during the acute injury period. MSC treatment promoted the transition from Ly6Chi to Ly6Clo population, inhibit the proinflammatory function of monocytes and promote the lysosomal function of MoMF. Furthermore, MSCs attenuated the recruitment of neutrophils by reducing the expression of CXCL2 of MoMF. MoMF with high expression of arginase 1 appeared during the recovery period, and MSCs could increase their expression of arginase 1, which may promote liver repair. To sum up, we demonstrated the characteristics of distinct MoMF during different periods of ALI and revealed their functional changes after MSC treatment, providing immunotherapeutic targets for MSC treatment of ALI.

Hepatoprotective effect and structural analysis of Hedysarum polysaccharides in vivo and in vitro

The crude Hedysarum polysaccharides (HPS: HPS-50 and HPS-80) obtained from Radix Hedysari exhibited great pharmacological activities in our previous research. This study investigated the effects of HPS on lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced acute liver injury (ALI) in mice and LPS-induced injury in LO2 cells, as well as the relationship between structural characteristics and hepatoprotective activities. The in vivo results showed that compared with HPS-80, HPS-50 showed stronger hepatoprotection, which improved histopathological changes to normal levels. HPS-50 significantly decreased the levels of ALT, AST, MPO, and MDA, increased the activities of SOD, CAT, and GSH, and suppressed the LPS/D-GalN-triggered production of TNF-α, IL-1β, and IL-6 (p < .05). The results in vitro showed that HPS-50-P (HPS-50-1, HPS-50-2, and HPS-50-3) purified from HPS-50 played significant protective roles against LPS-induced injury in LO2 cells by reducing cell apoptosis and relieving cell cycle arrest. HPS-50-2 restored the percentage of normal cells from 54.8% to 94.7%, and reduced the S phase cells from 59.40% to 47.05% (p < .01). By analyzing the structure of HPS-50-P, including monosaccharide composition, molecular weight, chain conformation, and surface morphology, we speculated that the best protective effect of HPS-50-2 might be attributed to its beta configuration, highest molecular weight, and high glucose and galactose contents. These findings indicate that HPS-50 might be a promising source of functional foods for the protection and prevention of ALI. PRACTICAL APPLICATIONS: In this study, the protective effect of HPS on ALI was evaluated from multiple perspectives, and HPS-50-2 was screened as a potential active ingredient. This study has two practical applications. First, it provides a new way to improve ALI, and a new option for patients to prevent and treat ALI. Second, this work also complements the pharmacological activity of Radix Hedysari and provides a basis for the development of Radix Hedysari as a functional food.

Diagnostic role of simple indices in HCV-related liver cirrhosis outcomes: a prospective cross-sectional study

Aim of the study

To evaluate the diagnostic performance of neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), albumin-bilirubin ratio (ABR) and albumin-bilirubin score (ALBI) in different outcomes of liver cirrhosis, including decompensated liver cirrhosis (DLC), acute-on-chronic liver failure (ACLF), hepatocellular carcinoma (HCC), and spontaneous bacterial peritonitis (SBP). A second objective was to find their cut-off values. Finally, we aimed to correlate these indices with the severity of liver cirrhosis.

Material and methods

The study included 149 patients with hepatitis C virus (HCV)-related liver cirrhosis. They were categorized into 3 groups according to severity of cirrhosis as compensated cirrhosis, decompensated liver cirrhosis and acute-on-chronic liver failure based on Child-Turcotte-Pugh (CTP) and MELD-Na scores. Patients were categorized according to presence of HCC and spontaneous bacterial peritonitis. All patients had a complete blood picture and liver profile. NLR, PLR, ALBI and ABR were calculated.

Results

NLR, PLR, ALBI and ABR correlated with CTP, and MELD-Na scores. NLR > 6.27 can be used to predict SBP in patients with ascites. NLR cut-off value > 3.61 and > 5.26 can be used to predict DLC and ACLF respectively in liver cirrhosis. ABR < 0.90 discriminated ACLF from DLC with OR = 2.93 (95% CI).

Conclusions

The simple inflammatory scores NLR and PLR together with simple ABR and ALBI scores can be used as quick tools to assess severity of liver cirrhosis. NLR can predict the presence of SBP in patients with ascites. ABR is superior to ALBI in discriminating ACLF from DLC.

Glucocorticoid Treatment Strategies in Liver Failure

Liver failure is characterized by serious liver decompensation and high mortality. The activation of systemic immune responses and systemic inflammation are widely accepted as the core pathogenesis of liver failure. Glucocorticoids (GCs) are most regularly utilized to suppress excessive inflammatory reactions and immunological responses. GCs have been used in the clinical treatment of liver failure for nearly 60 years. While there has been no unanimity on the feasibility and application of GC treatment in liver failure until recently. The most recent trials have produced conflicting results when it comes to the dose and time for GC therapy of different etiology of liver failure. Our review outlines the issues and options in managing GC treatment in liver failure based on an investigation of the molecular mechanism that GC may give in the treatment.

Characteristics of Computed Tomography Images for Patients with Acute Liver Injury Caused by Sepsis under Deep Learning Algorithm

This study was aimed at exploring the application of image segmentation based on full convolutional neural network (FCN) in liver computed tomography (CT) image segmentation and analyzing the clinical features of acute liver injury caused by sepsis. The Sigmoid function, encoder-decoder, and weighted cross entropy loss function were introduced and optimized based on FCN. The Dice value, precision, recall rate, volume overlap error (VOE), relative volume difference (RVD), and root mean square error (RMSE) values of the optimized algorithms were compared and analyzed. 92 patients with sepsis were selected as the research objects, and they were divided into a nonacute liver injury group (50 cases) and acute liver injury group (42 cases) based on whether they had acute liver injury. The differences in the proportion of patients with different disease histories, the proportion of patients with different infection sites, the number of organ failure, and the time of admission to intensive care unit (ICU) were compared between the two groups. It was found that the optimized window CT image Dice value after preprocessing (0.704 ± 0.06) was significantly higher than the other two methods (P < 0.05). The Dice value, precision, and recall rate of the optimized-FCN algorithm were (0.826 ± 0.06), (0.91 ± 0.08), and (0.88 ± 0.09), respectively, which were significantly higher than other algorithms (P < 0.05). The VOE, RVD, and RMSE values were (21.19 ± 1.97), (10.45 ± 1.02), and (0.25 ± 0.02), respectively, which were significantly lower than other algorithms (P < 0.05). The proportion of patients with a history of drinking in the nonacute liver injury group was lower than that in the acute liver injury group (P < 0.05), and the proportion of patients with a history of hypotension was greatly higher than that in the nonacute liver injury group (P < 0.01). CT images of sepsis patients with acute liver injury showed that large areas of liver parenchyma mixed with high-density hematoma, the number of organ failures, and the length of stay in ICU were significantly higher than those in the nonacute liver injury group (P < 0.05). It showed that the optimization algorithm based on FCN greatly improved the performance of CT image segmentation. Long-term drinking, low blood pressure, number of organ failures, and length of stay in ICU were all related to sepsis and acute liver injury. Conclusion in this study could provide a reference basis for the diagnosis and prognosis of acute liver injury caused by sepsis.

Negative Immune Checkpoint Protein, VISTA, Regulates the CD4+ Treg Population During Sepsis Progression to Promote Acute Sepsis Recovery and Survival

Sepsis is a systemic immune response to infection that is responsible for ~35% of in-hospital deaths and over 24 billion dollars in annual treatment costs. Strategic targeting of non-redundant negative immune checkpoint protein pathways can cater therapeutics to the individual septic patient and improve prognosis. B7-CD28 superfamily member V-domain Immunoglobulin Suppressor of T cell Activation (VISTA) is an ideal candidate for strategic targeting in sepsis. We hypothesized that immune checkpoint regulator, VISTA, controls T-regulatory cells (Treg), in response to septic challenge, thus playing a protective role/reducing septic morbidity/mortality. Further, we investigated if changes in morbidity/mortality are due to a Treg-mediated effect during the acute response to septic challenge. To test this, we used the cecal ligation and puncture model as a proxy for polymicrobial sepsis and assessed the phenotype of CD4+ Tregs in VISTA-gene deficient (VISTA-/-) and wild-type mice. We also measured changes in survival, soluble indices of tissue injury, and circulating cytokines in the VISTA-/- and wild-type mice. We found that in wild-type mice, CD4+ Tregs exhibit a significant upregulation of VISTA which correlates with higher Treg abundance in the spleen and small intestine following septic insult. However, VISTA-/- mice have reduced Treg abundance in these compartments met with a higher expression of Foxp3, CTLA4, and CD25 compared to wild-type mice. VISTA-/- mice also have a significant survival deficit, higher levels of soluble indicators of liver injury (i.e., ALT, AST, bilirubin), and increased circulating proinflammatory cytokines (i.e., IL-6, IL-10, TNFα, IL-17F, IL-23, and MCP-1) following septic challenge. To elucidate the role of Tregs in VISTA-/- sepsis mortality, we adoptively transferred VISTA-expressing Tregs into VISTA-/- mice. This adoptive transfer rescued VISTA-/- survival to wild-type levels. Taken together, we propose a protective Treg-mediated role for VISTA by which inflammation-induced tissue injury is suppressed and improves survival in early-stage murine sepsis. Thus, enhancing VISTA expression or adoptively transferring VISTA+ Tregs in early-stage sepsis may provide a novel therapeutic approach to ameliorate inflammation-induced death.

Current Advances of Innate and Adaptive Immunity in Acute-on-Chronic Hepatitis B Liver Failure

Abstract

Acute-on-chronic hepatitis B liver failure (ACHBLF) is a term used to define the acute deterioration of liver function that occurs in patients with chronic hepatitis B virus infection or hepatitis B virus-related liver cirrhosis. The specific pathogenesis of ACHBLF is still not completely understood. Current research has shown that an intense systemic inflammation is involved in the development of acute-on-chronic liver failure (ACLF). Meanwhile, a subsequent immune paresis over the course of ACLF favors the development of infection and sepsis. Deregulation in both the innate and adaptive immunity is the notable feature of ACLF. The dysregulated immune responses play a crucial role in disease progression and potentially drive organ failure and mortality in ACHBLF. In this review, we highlight the current knowledge of innate and adaptive immune cells in ACHBLF.

Proceedings of ESPGHAN Monothematic Conference 2020: "Acute Liver Failure in Children": Diagnosis and Initial Management

OBJECTIVES

The Hepatology Committee of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) aims to educate pediatric gastroenterologists, members of ESPGHAN and professionals from other specialties promoting an exchange of clinical expertise in the field of pediatric hepatology. Herewith we have concentrated on detailing the recent advances in acute liver failure in infants and children.

METHODS

The 2020 ESPGHAN monothematic three-day conference on pediatric hepatology disease, entitled "acute liver failure" (ALF), was organized in Athens, Greece. ALF is a devastating disease with high mortality and most cases remain undiagnosed. As knowledge in diagnosis and treatment of ALF in infants and children has increased in the past decades, the objective was to update physicians in the field with the latest research and developments in early recognition, curative therapies and intensive care management, imaging techniques and treatment paradigms in these age groups.

RESULTS

In the first session, the definition, epidemiology, various causes of ALF, in neonates and older children and recurrent ALF (RALF) were discussed. The second session was dedicated to new aspects of ALF management including hepatic encephalopathy (HE), coagulopathy, intensive care interventions, acute on chronic liver failure, and the role of imaging in treatment and prognosis. Oral presentations by experts in various fields are summarized highlighting key learning points.

CONCLUSIONS

The current report summarizes the major learning points from this meeting. It also identifies areas where there is gap of knowledge, thereby identifying the research agenda for the near future.

The dynamics of cell death patterns and regeneration during acute liver injury in mice

Acute liver injury is a serious clinical syndrome with multiple causes and unclear pathological process. Here, CCl₄‐ and D‐galactosamine/lipopolysaccharide (D‐gal/LPS)‐induced acute liver injury was established to explore the cell death patterns and determine whether or not liver regeneration occurred. In CCl₄‐induced hepatic injury, three phases, including the early, progressive, and recovery phase, were considered based on alterations of serum transaminases and liver morphology. Moreover, in this model, cytokines exhibited double‐peak fluctuations; apoptosis and pyroptosis persisted throughout all phases; autophagy occurred in the early and the progressive phases; and sufficient and timely hepatocyte regeneration was observed only during the recovery phase. All of these phenomena contribute to mild liver injury and subsequent regeneration. Strikingly, only the early and progressive phases were observed in the D‐gal/LPS model. Slight pyroptosis occurred in the early phase but diminished in the progressive phase, while apoptosis, reduced autophagy, and slight but subsequently diminished regeneration occurred only during the progressive phase, accompanied by a strong cytokine storm, resulting in severe liver injury with high mortality. Taken together, our work reveals variable modes and dynamics of cell death and regeneration, which lead to different consequences for mild and severe acute liver injury, providing a helpful reference for clinical therapy and prognosis.

Hepatoprotective effect of diallyl trisulfide against lipopolysaccharide and D-galactosamine induced acute liver failure in mice via suppressing inflammation and apoptosis

Acute liver failure (ALF), characterized by the quick occurrence of disorder in liver, is a serious liver injury with extremely high mortality. Therefore, we investigated whether diallyl trisulfide (DATS), a natural product from garlic, protected against ALF in mice and studied underlying mechanisms. In the present study, lipopolysaccharide (LPS) (10 μg·kg^-1)/D-galactosamine (D-gal) (500 mg·kg^-1) was intraperitoneally injected to ICR mice to induce ALF. The mice were orally administered 20-, 40-, or 80-mg·kg^-1 DATS) 1 h before LPS/D-gal exposure. Serum biochemical analyses and pathological study found that DATS pretreatment effectively prevented the ALF in LPS/D-gal-treated mice. Mechanistically, pretreatment of DATS inhibited the increase of the numbers of CD11b⁺ Kupffer cells and other macrophages in the liver, the release of tumor necrosis factor-α into the blood, and Caspase-1 activation induced by LPS/D-gal treatment in mice. Furthermore, DATS inhibited the activation of Caspase-3, downregulation of Bcl-2/Bax ratio, and increase of TUNEL positive staining. Altogether, our findings suggest that DATS exhibits hepatoprotective effects against ALF elicited by LPS/D-gal challenge, which probably associated with anti-inflammation and anti-apoptosis.

Scavenger Receptors: Novel Roles in the Pathogenesis of Liver Inflammation and Cancer

The scavenger receptor superfamily represents a highly diverse collection of evolutionarily-conserved receptors which are known to play key roles in host homeostasis, the most prominent of which is the clearance of unwanted endogenous macromolecules, such as oxidized low-density lipoproteins, from the systemic circulation. Members of this family have also been well characterized in their binding and internalization of a vast range of exogenous antigens and, consequently, are generally considered to be pattern recognition receptors, thus contributing to innate immunity. Several studies have implicated scavenger receptors in the pathophysiology of several inflammatory diseases, such as Alzheimer's and atherosclerosis. Hepatic resident cellular populations express a diverse complement of scavenger receptors in keeping with the liver's homeostatic functions, but there is gathering interest in the contribution of these receptors to hepatic inflammation and its complications. Here, we review the expression of scavenger receptors in the liver, their functionality in liver homeostasis, and their role in inflammatory liver disease and cancer.

The patient with cirrhosis in the intensive care unit and the management of acute-on-chronic liver failure

Acute on chronic liver failure (ACLF) is a clinical syndrome characterised by acute hepatic decompensation, multi-organ failure and high mortality, in patients with cirrhosis.  Organ dysfunction in ACLF is often reversible and when necessary these patients should be considered appropriate candidates for admission to an intensive care unit (ICU). The yearly increase in numbers of patients with ACLF admitted to ICU has been matched with an improvement in survival.  ACLF has only been recently defined. In the absence of evidence-based guidelines we outline a systems-based approach to care which encompasses accepted ICU practice and evidence from trials in this cohort. We advocate for timely referral to specialist liver centres and consider the complexities of proceeding with liver transplantation. Equally, in a proportion of patients who continue to deteriorate, appropriate ceilings of care should be established.  Future clinical trials may change treatment paradigms but care of patients with ACLF is undoubtedly becoming an integral part of an intensivist's practice. We hope that this review is a welcome starting point when managing this complex clinical syndrome.

The Protective Effects of a Modified Xiaohua Funing Decoction against Acute Liver Failure in Mice Induced by D-Gal and LPS

Objective

The aim of this study was to evaluate the effects of a modified Xiaohua Funing decoction (Xfd) on acute liver failure (ALF) and determine whether the protective mechanisms are related to alterations in the gut microbiota.

Methods

An animal model of ALF was induced by intraperitoneal injection of D-galactosamine (D-Gal, 0.5 g/kg) and lipopolysaccharide (LPS, 100 μg/kg). Male BALB/c mice were randomly divided into the following 4 groups: the control group (saline, Con), model group (D-Gal/LPS, Mod), silymarin pretreatment group (200 mg/kg, Sil), and modified Xfd pretreatment group (650 mg/kg, Xfd). The Sil and Xfd groups received the respective intervention orally for 14 days and 2 h before D-Gal/LPS treatment. The liver injury markers included alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and liver histology. 16S rRNA gene sequencing was performed to assess the effects on the caecum content.

Results

D-Gal/LPS treatment caused severe ALF, illustrating that the ALF model was successfully established. The administration of Sil and Xfd greatly reduced the serum ALT and AST levels and improved the pathological signs of liver injury. However, no significant difference was found between the two groups. In contrast to the Mod group, the Sil and Xfd groups showed a shift toward the Con group in terms of the gut microbiota structure. The abundances of Firmicutes and Bacteroidetes and the Bacteroidetes/Firmicutes ratio in the Mod group significantly differed from those in the Con group. The Sil and Xfd groups showed restoration of the disordered microbiota. Significantly increased relative abundances of Lachnospiraceae_NK4A136_group and Candidatus_Saccharimonas and a markedly decreased Muribaculaceae abundance were found in the Sil and Xfd mice compared with those in the Mod mice (P < 0.01, P < 0.05). Interestingly, a negative correlation was observed between the abundances of the gut microbiota constituents, specifically Clostridia_UCG-014, and ALT and AST levels.

Conclusion

In summary, our results indicate that Xfd may protect the liver and modify the gut microbiota in ALF mice.

TAM Receptors in the Pathophysiology of Liver Disease

TAM receptors (Tyro3, Axl and MerTK) are a family of tyrosine kinase receptors that are expressed in a variety of cell populations, including liver parenchymal and non-parenchymal cells. These receptors are vital for immune homeostasis, as they regulate the innate immune response by suppressing inflammation via toll-like receptor inhibition and by promoting tissue resolution through efferocytosis. However, there is increasing evidence indicating that aberrant TAM receptor signaling may play a role in pathophysiological processes in the context of liver disease. This review will explore the roles of TAM receptors and their ligands in liver homeostasis as well as a variety of disease settings, including acute liver injury, steatosis, fibrosis, cirrhosis-associated immune dysfunction and hepatocellular carcinoma. A better understanding of our current knowledge of TAM receptors in liver disease may identify new opportunities for disease monitoring as well as novel therapeutic targets. Nonetheless, this review also aims to highlight areas where further research on TAM receptor biology in liver disease is required.

HMGB1-Induced Hepatocyte Pyroptosis Expanding Inflammatory Responses Contributes to the Pathogenesis of Acute-on-Chronic Liver Failure (ACLF)

Background

Acute-on-chronic liver failure (ACLF) is a critical disease with a high fatality rate. Immune dysfunction and inflammatory responses are key risk factors in ACLF. Pyroptosis is a form of programmed cell death characterized by the release of inflammatory cytokines, which causes the strong inflammatory responses. High mobility group box-1 (HMGB1) could induce pyroptosis and is closely related to ACLF. However, the role of HMGB1-induced hepatocyte pyroptosis in ACLF has never been proposed; whether HMGB1-induced hepatocyte pyroptosis participates in the development of ACLF and the mechanisms involved are barely understood.

Purpose

This study aimed to clarify the roles of HMGB1-induced hepatocyte pyroptosis in ACLF and the molecular mechanisms involved.

Methods

Wistar rats were randomly divided into five groups, viz.: Normal, ACLF model, HMGB1 inhibitor, Caspase-1 inhibitor, and HMGB1 inhibitor+Caspase-1 inhibitor groups. The ACLF rat model was established using 40% carbon tetrachloride-induced liver fibrosis, followed by D-galactosamine and lipopolysaccharide joint acute attacks. The liver function, coagulation function and pathological damage of rats in each group were evaluated. The biological mechanisms of HMGB1-induced pyroptosis and the release of inflammatory cytokines were investigated using Western blot, quantitative real-time PCR (RT-qPCR), immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay.

Results

The liver function and coagulation function of ACLF rats were seriously impaired; liver tissue showed massive or submassive necrosis, accompanied by inflammatory cell infiltration; the percentage of pyroptotic hepatocytes significantly increased, and a large number of inflammatory cytokines were released. The expression levels of pyroptosis-related genes and proteins in liver tissues and serum significantly increased. But these phenomenons were improved by the inhibition of HMGB1, and the dual inhibition of HMGB1 and Caspase-1 showed a stronger effect.

Conclusion

The findings indicate, for the first time, that pyroptosis is a crucial pathophysiological event of ACLF involved in its pathogenesis, and HMGB1-induced hepatocyte pyroptosis expands inflammatory responses to aggravate ACLF, suggesting that it may be a potential therapeutic target for ACLF treatment.

Transcriptional and Epigenetic Regulation of Monocyte and Macrophage Dysfunction by Chronic Alcohol Consumption

Drinking alcohol, even in moderation, can affect the immune system. Studies have shown disproportionate effects of alcohol on circulating and tissue-resident myeloid cells (granulocytes, monocytes, macrophages, dendritic cells). These cells orchestrate the body's first line of defense against microbial challenges as well as maintain tissue homeostasis and repair. Alcohol's effects on these cells are dependent on exposure pattern, with acute drinking dampening but chronic drinking enhancing production of inflammatory mediators. Although chronic drinking is associated with heightened systemic inflammation, studies on tissue resident macrophage populations in several organs including the spleen, liver, brain, and lung have also shown compromised functional and metabolic capacities of these cells. Many of these effects are thought to be mediated by oxidative stress caused by alcohol and its metabolites which can directly impact the cellular epigenetic landscapes. In addition, since myeloid cells are relatively short-lived in circulation and are under constant repopulation from the bone marrow compartment, alcohol's effects on bone marrow progenitors and hematopoiesis are important for understanding the impact of alcohol systemically on these myeloid populations. Alcohol-induced disruption of progenitor, circulating, and tissue resident myeloid populations contribute to the increased susceptibility of patients with alcohol use disorders to viral and bacterial infections. In this review, we provide an overview of the impact of chronic alcohol consumption on the function of monocytes and macrophages in host defense, tissue repair and inflammation. We then summarize our current understanding of the mechanisms underlying alcohol-induced disruption and examine changes in transcriptome and epigenome of monocytes and mcrophages. Overall, chronic alcohol consumption leads to hyper-inflammation concomitant with decreased microbial and wound healing responses by monocytes/macrophages due to a rewiring of the epigentic and transcriptional landscape. However, in advanced alcoholic liver disease, myeloid cells become immunosuppressed as a response to the surrounding hyper-inflammatory milieu. Therefore, the effect of chronic alcohol on the inflammatory response depends on disease state and the immune cell population.

Immunomodulatory Activity of Granulocyte Colony-Stimulating Factor and its Therapeutic Effect on Liver Failure

Abstract

Liver failure is characterized by the rapid deterioration of liver function, often accompanied by ascites, coagulation dysfunction, hepatic encephalopathy, and other critical complications. Owing to the complex multifaceted pathogenesis and consequential clinical manifestations of the disease, liver failure displays poor prognosis and warrants comprehensive clinical treatment and management. Liver transplantation remains the only well-established treatment for liver failure. However, several factors including transplantation cost and low organ donation rates limit the rate of liver transplantation. The development of a suitable therapy for liver failure is a significant challenge and remains a cause of concern for the medical world. Granulocyte colony-stimulating factor (G-CSF), a member of the cytokine family of hematopoietic growth factors, is involved in the migration of hematopoietic stem cells into the damaged liver, and effectuates their dedifferentiation into hepatocytes. Liver regeneration involves a complex crosstalk of multiple cell types, including hepatocytes, endothelial cells, and inflammatory cells. Neutrophils and monocytes/macrophages that present different types of innate immune cells were found to play a crucial role in the progression of inflammation and restoration of the liver tissue. G-CSF, known as the most common used cytokine, may also affect these immune cells by combining G-CSF receptors on their surface. The immunomodulatory activity of G-CSF should be studied and described in order to ascertain its therapeutic effect on liver failure.

Macrophages as key regulators of liver health and disease

Macrophages are a heterogeneous population of innate immune cells and key cellular components of the liver. Hepatic macrophages consist of embryologically-derived resident Kupffer cells (KC), recruited monocyte-derived macrophages (MDM) and capsular macrophages. Both the diversity and plasticity of hepatic macrophage subsets explain their different functions in the maintenance of hepatic homeostasis and in injury processes in acute and chronic liver diseases. In this review, we assess the evidence for macrophage involvement in regulating both liver health and injury responses in liver diseases including acute liver injury (ALI), chronic liver disease (CLD) (including liver fibrosis) and hepatocellular carcinoma (HCC). In healthy livers, KC display critical functions such as phagocytosis, danger signal recognition, cytokine release, antigen processing and the ability to orchestrate immune responses and maintain immunological tolerance. However, in most liver diseases there is a striking hepatic MDM expansion, which orchestrate both disease progression and regression. Single-cell approaches have transformed our understanding of liver macrophage heterogeneity, dynamics, and functions in both human samples and preclinical models. We will further discuss the new insights provided by these approaches and how they are enabling high-fidelity work to specifically identify pathogenic macrophage subpopulations. Given the important role of macrophages in regulating injury responses in a broad range of settings, there is now a huge interest in developing new therapeutic strategies aimed at targeting macrophages. Therefore, we also review the current approaches being used to modulate macrophage function in liver diseases and discuss the therapeutic potential of targeting macrophage subpopulations as a novel treatment strategy for patients with liver disorders.

Liver dysfunction as a cytokine storm manifestation and prognostic factor for severe COVID-19

Liver damage in severe acute respiratory coronavirus 2 infection occurs in patients with or without preexisting liver disorders, posing a significant complication and mortality risk. During coronavirus disease 2019 (COVID-19), abnormal liver function is typically observed. However, liver injury may occur because of the treatment as well. Ischemia, cytokine storm, and hypoxia were identified as the three major factors contributing to liver damage during COVID-19. Indeed, raised liver enzymes during hospitalizations may be attributed to medications used, as well as sepsis and shock. As a result, the proportion of hospitalized patients afflicted with COVID-19 and pathological liver biomarkers varies from 14% to 53%. Aminotransferases and bilirubin are found most often elevated. Usually, increased gamma-glutamyltransferase, alkaline phosphatase, and decreased serum albumin levels are demonstrated. Additionally, although there is no specific treatment for COVID-19, many of the drugs used to treat the infection are hepatotoxic. In this mini-review, we focus on how liver dysfunction can be one of the features associated with the COVID-19 cytokine storm. Furthermore, data show that liver injury can be an independent predictor of severe COVID-19, the need for hospitalization, and death.

Human umbilical cord mesenchymal stem cells ameliorate acute liver failure by inhibiting apoptosis, inflammation and pyroptosis

Background

Human umbilical cord mesenchymal stem cells (UC-MSCs) are multipotent progenitor cells representing an attractive therapeutic tool for tissue damage and inflammation owing to their unique immunomodulatory properties. This study was designed to determine the protective effects and underlying mechanisms of UC-MSCs on acute liver failure (ALF).

Methods

ALF was induced in mice by intraperitoneal injection of D-galactosamine (D-GalN) and lipopolysaccharide (LPS). Mice were intravenously injected with 1×10⁶ UC-MSCs one hour before or six hours after D-GalN/LPS injection. Liver function was valued by serum biochemical parameters and hematoxylin-eosin staining. Inflammatory cytokine and chemokine levels were measured by real-time PCR, and inflammatory cells infiltration was observed by immunofluorescence staining. Hepatocyte apoptosis and pyroptosis related proteins were detected by western blot. Murine macrophage Raw264.7 in the presentation of LPS was treated with the UC-MSCs condition medium (UC-MSCs-CM), and then the levels of inflammatory cytokines and NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in Raw264.7 were measured.

Results

UC-MSCs significantly reduced the mortality, decreased serum alanine aminotransferase and aspartate aminotransferase levels, and improved the pathological damage. Moreover, UC-MSCs inhibited inflammatory cytokine and chemokine levels, especially TNF-α, interleukins-6 (IL-6), IL-1β, monocyte chemoattractant protein (MCP-1), CC-chemokines ligand 2 (CCL2), C-X-C motif ligand 2 (CXCL2), and reduced macrophage, neutrophil and T lymphocyte infiltration into the liver tissue. UC-MSCs also attenuated hepatocyte apoptosis, as evidenced by decreased TUNEL positive cells, increased Bcl-xl/Bax protein ratio and downregulated cleaved caspase 3 levels. NLRP3 inflammasome activation, IL-1β maturation and cleaved caspase1 were suppressed by UC-MSC administration. Furthermore, the UC-MSCs-CM reduced the levels of inflammatory cytokines and the activation of NLRP3 inflammasome in Raw264.7.

Conclusions

Our results demonstrated that UC-MSCs exerted therapeutic effects on ALF by inhibiting apoptosis, inflammation, and pyroptosis.

The Protective Effects of Zornia diphylla (L.) Pers. Against Acute Liver Injury Induced by Carbon Tetrachloride in Mice

Background:Zornia diphylla (L.) Pers. (ZDP) is a traditional Chinese herbal medicine that has been used for several decades to treat patients with liver diseases. Whether ZDP is best administered as a single agent or adjunctive therapy has yet to be determined as does the mechanism whereby it exerts its effects on antagonizing acute liver injury (ALI).

Aim of the study: To investigate the protective effects of ZDP on ALI induced by carbon tetrachloride (CCl₄) and the potential underlying mechanisms.

Materials and Methods: Sixty adult mice were randomized into six study groups (n = 10/group). Three groups were treated with different concentrations of ZDP (2.5, 1.25, 0.625 g/kg), one with bifendate (0.0075 g/kg) alone (positive control) and one with physiologic saline (normal, negative control). All groups were treated for 14 days. Two hours after the last administration, the normal group received an intraperitoneal injection of peanut oil, and the other five groups received an intraperitoneal injection of an equal dose of CCl₄ peanut oil solution. At 24 h, the liver index, histology and serum or tissue levels and/or protein expression of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBIL), alkaline phosphatase (ALP), superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), glutathione (GSH), Akt, phosphorylated Akt (p-Akt), nuclear factor kappa B p65 (NF-κB p65), inhibitor of NF-κB α (IκB-α), interleukin-1 β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), E-cadherin and vimentin were determined.

Results: Compared to the model controls, the degree of inflammatory cell infiltration and hepatocyte injury of liver tissue was relieved in the bifendate and three ZDP groups; liver index in the ZDP (2.5, 1.25 g/kg) groups and serum liver function indices in the ZDP (2.5, 1.25 and 0.625 g/kg) groups were decreased; antioxidants SOD, CAT and GSH in liver tissue were increased but the lipid peroxidation index MDA was decreased; protein expression of inflammatory cytokines Akt, p-Akt, NF-κB p65, IκB-α, IL-1β, IL-6 and TNF-α in the liver was ameliorated, and E-cadherin expression was increased. The results of liver histopathology also showed that ZDP had a significant effect on ALI.

Conclusion: ZDP has obvious protective effects on CCl₄-induced ALI as a single therapy and appears to act by inhibiting oxidation, reducing the release of inflammatory factors and promoting hepatocyte repair.

Therapeutic Modulation of the Host Defense by Hemoadsorption with CytoSorb®-Basics, Indications and Perspectives-A Scoping Review

The "normal" immune response to an insult triggers a highly regulated response determined by the interaction of various immunocompetent cells with pro- and anti-inflammatory cytokines. Under pathologic conditions, the massive elevation of cytokine levels ("cytokine storm") could not be controlled until the recent development of hemoadsorption devices that are able to extract a variety of different DAMPs, PAMPs, and metabolic products from the blood. CytoSorb® has been approved for adjunctive sepsis therapy since 2011. This review aims to summarize theoretical knowledge, in vitro results, and clinical findings to provide the clinician with pragmatic guidance for daily practice. English-language and peer-reviewed literature identified by a selective literature search in PubMed and published between January 2016 and May 2021 was included. Hemoadsorption can be used successfully as adjunct to a complex therapeutic regimen for various conditions. To the contrary, this nonspecific intervention may potentially worsen patient outcomes in complex immunological processes. CytoSorb® therapy appears to be safe and useful in various diseases (e.g., rhabdomyolysis, liver failure, or intoxications) as well as in septic shock or cytokine release syndrome, although a conclusive assessment of treatment benefit is not possible and no survival benefit has yet been demonstrated in randomized controlled trials.

Acute-on-Chronic Liver Failure: Pathophysiological Mechanisms and Management

Acute-on-chronic liver failure (ACLF) is a multifaceted condition with poor treatment options and high short-term mortality. ACLF can develop in patients with or without liver cirrhosis, where patients with decompensated cirrhosis display a higher risk of short-term mortality. Pathophysiological mechanisms include systemic inflammation due to bacterial and fungal infections and acute hepatic insult with drug, alcohol, and viral hepatitis. Cryptogenic factors also contribute to the development of ACLF. The clinical outcome of patients with ACLF gets further complicated by the occurrence of variceal hemorrhage, hepatorenal syndrome, hepatic encephalopathy, and systemic immune dysfunction. Regardless of the better understanding of pathophysiological mechanisms, no specific and definitive treatment is available except for liver transplantation. The recent approach of regenerative medicine using mesenchymal stem cells (MSCs) could be advantageous for the treatment of ACLF as these cells can downregulate inflammatory response by inducing antiinflammatory events and prevent hepatic damage and fibrosis by inhibiting hepatic stellate cell activation and collagen synthesis. Moreover, MSCs are involved in tissue repair by the process of liver regeneration. Considering the broad therapeutic potential of MSCs, it can serve as an alternative treatment to liver transplant in the near future, if promising results are achieved.

Expression of peripheral monocytic programmed death ligand-1 in severe sepsis combined with HBV-related cirrhosis. A pilot observational study

Introduction

Hepatitis B virus (HBV)-related liver cirrhosis (LC) complicated with severe sepsis (SS) leads to HBV-related acute-on-chronic liver failure (HBV-ACLF). Programmed cell death ligand-1 (PD-L1)-associated immunosuppression is involved in both LC and SS. This study aimed to examine the expression and clinical relevance of PD-L1 on peripheral CD14+ monocytes in sepsis-induced HBV-ACLF.

Material and methods

PD-L1 expression on peripheral CD14+ monocytes among the healthy control (HC), LC and LC + SS groups was examined using flow cytometry analysis and compared. In the LC + SS group, an SS-induced ACLF subgroup was identified. LC + SS patients were followed up for 28 days. The correlations between monocytic PD-L1 expression and illness severity scores and the prognostic value of monocytic PD-L1 expression in SS-induced HBV-ACLF patients was examined.

Results

There were 17, 30 and 70 participants in the HC, LC and LC + SS groups, respectively. The monocytic PD-L1 expression was higher in the LC group compared with the HC group and in the LC + SS group compared with the LC group. The monocytic PD-L1 expression was positively correlated with the illness severity scores in LC + SS patients and predicted 28-day mortality of SS-induced HBV-ACLF patients (n = 59).

Conclusions

Severe sepsis exhibits a superimposed effect of monocytic PD-L1 up-regulation on the basis of liver cirrhosis, and monocytic PD-L1 expression predicts 28-day mortality of SS-induced HBV-ACLF.

The Gut-Liver Axis in Chronic Liver Disease: A Macrophage Perspective

Chronic liver disease (CLD) is a growing health concern which accounts for two million deaths per year. Obesity, alcohol overconsumption, and progressive cholestasis are commonly characterized by persistent low-grade inflammation and advancing fibrosis, which form the basis for development of end-stage liver disease complications, including hepatocellular carcinoma. CLD pathophysiology extends to the intestinal tract and is characterized by intestinal dysbiosis, bile acid dysregulation, and gut barrier disruption. In addition, macrophages are key players in CLD progression and intestinal barrier breakdown. Emerging studies are unveiling macrophage heterogeneity and driving factors of their plasticity in health and disease. To date, in-depth investigation of how gut-liver axis disruption impacts the hepatic and intestinal macrophage pool in CLD pathogenesis is scarce. In this review, we give an overview of the role of intestinal and hepatic macrophages in homeostasis and gut-liver axis disruption in progressive stages of CLD.

Cellular and Molecular Mechanisms Underlying Liver Fibrosis Regression

Chronic liver injury of different etiologies may result in hepatic fibrosis, a scar formation process consisting in altered deposition of extracellular matrix. Progression of fibrosis can lead to impaired liver architecture and function, resulting in cirrhosis and organ failure. Although fibrosis was previous thought to be an irreversible process, recent evidence convincingly demonstrated resolution of fibrosis in different organs when the cause of injury is removed. In the liver, due to its high regenerative ability, the extent of fibrosis regression and reversion to normal architecture is higher than in other tissues, even in advanced disease. The mechanisms of liver fibrosis resolution can be recapitulated in the following main points: removal of injurious factors causing chronic hepatic damage, elimination, or inactivation of myofibroblasts (through various cell fates, including apoptosis, senescence, and reprogramming), inactivation of inflammatory response and induction of anti-inflammatory/restorative pathways, and degradation of extracellular matrix. In this review, we will discuss the major cellular and molecular mechanisms underlying the regression of fibrosis/cirrhosis and the potential therapeutic approaches aimed at reversing the fibrogenic process.

Multiple organ involvement and ICU considerations for the care of acute liver failure (ALF) and acute on chronic liver failure (ACLF) in children

Liver disease results in approximately 15,000 pediatric hospitalizations per year in the United States and is a significant burden to child health. Major etiologies of liver failure and indications for transplantation in children include: biliary atresia, metabolic/genetic conditions, toxins, infections, tumors, and immune-mediated liver/biliary injury. Children requiring transplantation are placed on the United Network of Organ Sharing waitlist including those with acute liver failure (ALF) and acute on chronic liver failure (ACLF). ALF is a clinical syndrome in which a previously healthy child develops rapid-onset hepatic dysfunction, and becomes critically ill with multiple organ dysfunction within days. ACLF, by contrast, is generally described as an acute decompensation of pre-existing chronic liver disease (CLD) brought on by a precipitating event, with higher risk of mortality. Children with ALF and ACLF receive multidisciplinary care in pediatric intensive care units (ICUs) due to multiple organ system involvement and high risk of decompensation in these patients. The care of these patients requires a holistic approach that addresses the complex interplay between hepatic and extra-hepatic organ systems. This review will define and describe ALF and ACLF in the pediatric population, and outline the effects of ALF and ACLF on individual organ systems with diagnostic and management considerations in the ICU while awaiting liver transplantation.

Cell-Based Regeneration and Treatment of Liver Diseases

The liver, in combination with a functional biliary system, is responsible for maintaining a great number of vital body functions. However, acute and chronic liver diseases may lead to irreversible liver damage and, ultimately, liver failure. At the moment, the best curative option for patients suffering from end-stage liver disease is liver transplantation. However, the number of donor livers required by far surpasses the supply, leading to a significant organ shortage. Cellular therapies play an increasing role in the restoration of organ function and can be integrated into organ transplantation protocols. Different types and sources of stem cells are considered for this purpose, but highly specific immune cells are also the focus of attention when developing individualized therapies. In-depth knowledge of the underlying mechanisms governing cell differentiation and engraftment is crucial for clinical implementation. Additionally, novel technologies such as ex vivo machine perfusion and recent developments in tissue engineering may hold promising potential for the implementation of cell-based therapies to restore proper organ function.

The Jieduan-Niwan (JDNW) Formula Ameliorates Hepatocyte Apoptosis: A Study of the Inhibition of E2F1-Mediated Apoptosis Signaling Pathways in Acute-on-Chronic Liver Failure (ACLF) Using Rats

Background

Acute-on-chronic liver failure (ACLF) is a severe, complicated human disease. E2F1-mediated apoptosis plays an important role in ACLF development. Jieduan-Niwan (JDNW) formula, a traditional Chinese medicine (TCM), has shown remarkable clinical efficacy in ACLF treatment. However, the hepatoprotective mechanisms of the formula are barely understood.

Purpose

This study aimed to investigate the mechanisms of JDNW formula in ACLF treatment by specifically regulating E2F1-mediated apoptotic signaling pathways in rats.

Methods

The JDNW components were determined by high-performance liquid chromatography (HPLC) analysis. The ACLF rat model was established using human serum albumin immune-induced liver cirrhosis, followed by D-galactosamine and lipopolysaccharide joint acute attacks. The ACLF rat was treated with JDNW formula. Prothrombin time activity was measured to investigate the coagulation function. Liver pathological injury was observed by hematoxylin-eosin (HE) and reticular fiber staining. The hepatocyte apoptosis index and apoptosis rate were determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and flow cytometry, respectively. Additionally, the expression of key genes and proteins that regulate E2F1-mediated apoptosis was analyzed by quantitative real-time PCR and Western blot.

Results

Seven major components of JDNW formula were detected. The formula ameliorated the coagulation function, decreased the hepatocyte apoptosis index and apoptosis rate, and alleviated liver pathological damage in ACLF rats. The down-regulation of the expression of genes and proteins from p53-dependent and non-p53-dependent apoptosis pathways and the up-regulation of the expression of genes from blocking anti-apoptotic signaling pathways indicated that JDNW formula inhibited excessive hepatocyte apoptosis in ACLF rats via E2F1-mediated apoptosis signaling pathways.

Conclusion

The findings indicate that JDNW formula protects livers of ACLF rats by inhibiting E2F1-mediated apoptotic signaling pathways, implying that these pathways might be a potential therapeutic target for ACLF treatment.

Acute myocardial injury secondary to severe acute liver failure: A retrospective analysis supported by animal data

To investigate whether acute liver failure (ALF) leads to secondary acute myocardial injury, 100 ALF patients that were retrospectively identified in a single center based on ICD 10 codes and 8 rats from an experimental study that died early after bile duct ligation (BDL) were examined. Creatine kinase (CK), creatine kinase-MB isoenzyme (CKMB) and cardiac troponin-I (cTnI) were analyzed as markers of myocardial injury. For histological analysis, hematoxylin-eosin (HE), elastic Van Gieson (EVG), CD41 and myeloperoxidase were used to stain rat hearts. Major adverse cardiac events (MACEs) were a critical factor for mortality (p = 0.037) in human ALF. Deceased patients exhibited higher levels of CKMB than survivors (p = 0.023). CKMB was a predictor of mortality in ALF (p = 0.013). Animals that died early after BDL exhibited increased cTnI, CKMB, tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) levels compared to controls (cTnI: p = 0.011, CKMB: p = 0.008, TNFα: p = 0.003, IL-6: p = 0.006). These animals showed perivascular lesions and wavy fibers, microthrombi and neutrophilic infiltration in the heart. MACEs are decisive for mortality in human ALF, and elevated CKMB values indicate that this might be due to structural myocardial damage. Accordingly, CKMB was found to have predictive value for mortality in ALF. The results are substantiated by data from a rat BDL model demonstrating diffuse myocardial injury.

Dysregulation of the Lysophosphatidylcholine/Autotaxin/Lysophosphatidic Acid Axis in Acute-on-Chronic Liver Failure Is Associated With Mortality and Systemic Inflammation by Lysophosphatidic Acid-Dependent Monocyte Activation

BACKGROUND & AIMS

Acute-on-chronic liver failure (ACLF) is characterized by systemic inflammation, monocyte dysfunction, and susceptibility to infection. Lysophosphatidylcholines (LPCs) are immune-active lipids whose metabolic regulation and effect on monocyte function in ACLF is open for study.

APPROACHES & RESULTS

Three hundred forty-two subjects were recruited and characterized for blood lipid, cytokines, phospholipase (PLA), and autotaxin (ATX) concentration. Peripheral blood mononuclear cells and CD14⁺ monocytes were cultured with LPC, or its autotaxin (ATX)-derived product, lysophosphatidic acid (LPA), with or without lipopolysaccharide stimulation and assessed for surface marker phenotype, cytokines production, ATX and LPA-receptor expression, and phagocytosis. Hepatic ATX expression was determined by immunohistochemistry. Healthy volunteers and patients with sepsis or acute liver failure served as controls. ACLF serum was depleted in LPCs with up-regulated LPA levels. Patients who died had lower LPC levels than survivors (area under the receiver operating characteristic curve, 0.94; P < 0.001). Patients with high-grade ACLF had the lowest LPC concentrations and these rose over the first 3 days of admission. ATX concentrations were higher in patients with AD and ACLF and correlated with Model for End-Stage Liver Disease, Consortium on Chronic Liver Failure-Sequential Organ Failure Assessment, and LPC/LPA concentrations. Reduction in LPC correlated with higher monocyte Mer-tyrosine-kinase (MerTK) and CD163 expression. Plasma ATX concentrations rose dynamically during ACLF evolution, correlating with IL-6 and TNF-α, and were associated with increased hepatocyte ATX expression. ACLF patients had lower human leukocyte antigen-DR isotype and higher CD163/MerTK monocyte expression than controls; both CD163/MerTK expression levels were reduced in ACLF ex vivo following LPA, but not LPC, treatment. LPA induced up-regulation of proinflammatory cytokines by CD14⁺ cells without increasing phagocytic capacity.

CONCLUSIONS

ATX up-regulation in ACLF promotes LPA production from LPC. LPA suppresses MerTK/CD163 expression and increases monocyte proinflammatory cytokine production. This metabolic pathway could be investigated to therapeutically reprogram monocytes in ACLF.