Pentraxin-3 modulates lipopolysaccharide-induced inflammatory response and attenuates liver injury

PTX3 exacerbates hepatocyte pyroptosis in hepatic ischemia-reperfusion injury by promoting macrophage M1 polarization

BACKGROUNDS

Hepatic ischemia-reperfusion injury (IRI) triggers macrophage activation, which in turn mediates inflammatory responses and affects tissue repair and injury severity. Pentraxin 3 (PTX3) is vital in immune regulation and inflammatory processes. In this study, we aim to investigate the potential role of PTX3 in macrophage-mediated hepatic IRI.

METHODS

Gene expression profiles and single-cell data were obtained from the Gene Expression Omnibus (GEO) database. Immunohistochemistry was used to evaluate the expression levels of PTX3, CD68, and CD86 in samples from the human and mouse hepatic IRI models. The effects of PTX3 knockdown or overexpression on macrophage polarization were assessed in Raw264.7. PTX3 knockdown/ overexpression in Raw264.7 and co-culturing with AML12 were performed under conditions of hypoxia-reoxygenation (H/R) to examine pyroptosis and injury in AML12.

RESULTS

PTX3 expression was significantly upregulated in both human and mouse hepatic IRI model samples. Bulk and single-cell RNA-seq data analyses revealed that PTX3 is associated with inflammatory response pathways and macrophage activation. Macrophages with high PTX3 expression exhibit M1-like characteristics. Similarly, overexpression of PTX3 promotes M1 polarization of Raw264.7 after H/R, while the knockdown group exhibits reduced M1 polarization. Co-culture results indicated that pyroptosis in AML12 was significantly reduced after H/R in the PTX3 knockdown group, whereas the PTX3 overexpression group exhibited the opposite outcome.

CONCLUSION

PTX3 regulates macrophage polarization during hepatic IRI, consequently influencing hepatocellular pyroptosis.

Pentraxin-3 modulates hepatocyte ferroptosis and the innate immune response in LPS-induced liver injury

The liver plays a crucial role in the immune response during endotoxemia and is one of the critical targets for sepsis-related injuries. As a secretory factor involved in inflammation, pentraxin-3 (PTX3) has been demonstrated to regulate hepatic homeostasis; however, the relationship between PTX3 and cell crosstalk between immune cells and hepatocytes in the liver remains incompletely understood. In this study, we revealed that, compared with WT mice, Ptx3-/- mice with lipopolysaccharide (LPS)-induced endotoxemia exhibited alleviated liver damage, with reduced serum alanine transaminase and aspartate transaminase levels and an improved survival rate. Mechanistically, RNA-Seq and western blot results revealed that Ptx3 knockdown in hepatocytes increased the expression of Tfrc and Ccl20; consequently, Ptx3 deficiency regulated LPS-induced hepatocyte ferroptosis via increased mitochondrial reactive oxygen species and Fe2+ and recruited more macrophages by CCL20/CCR6 axis to be involved in inflammation and the clearance of harmful substances. Moreover, western blot and immunofluorescence staining confirmed that the NF-κB signaling pathway was upregulated upon LPS treatment in Ptx3-knockdown macrophages, promoting phagocytosis and polarization toward M1 macrophages. Collectively, our findings show that the absence of Ptx3 can ameliorate sepsis-induced liver injury by regulating hepatocyte ferroptosis and promote the recruitment and polarization of M1 macrophages. These findings offer a key basis for the development of effective treatments for acute infections.

The role of forkhead box M1-methionine adenosyltransferase 2 A/2B axis in liver inflammation and fibrosis

Methionine adenosyltransferase 2 A (MAT2A) and MAT2B are essential for hepatic stellate cells (HSCs) activation. Forkhead box M1 (FOXM1) transgenic mice develop liver inflammation and fibrosis. Here we examine if they crosstalk in male mice. We found FOXM1/MAT2A/2B are upregulated after bile duct ligation (BDL) and carbon tetrachloride (CCl4) treatment in hepatocytes, HSCs and Kupffer cells (KCs). FDI-6, a FOXM1 inhibitor, attenuates the development and reverses the progression of CCl4-induced fibrosis while lowering the expression of FOXM1/MAT2A/2B, which exert reciprocal positive regulation on each other transcriptionally. Knocking down any of them lowers HSCs and KCs activation. Deletion of FOXM1 in hepatocytes, HSCs, and KCs protects from BDL-mediated inflammation and fibrosis comparably. Interestingly, HSCs from Foxm1Hep-/-, hepatocytes from Foxm1HSC-/-, and HSCs and hepatocytes from Foxm1KC-/- have lower FOXM1/MAT2A/2B after BDL. This may be partly due to transfer of extracellular vesicles between different cell types. Altogether, FOXM1/MAT2A/MAT2B axis drives liver inflammation and fibrosis.

Signal mining of adverse events of proteasome inhibitors in multiple myeloma based on FAERS

Objective

To mine and analyze adverse events (AEs) related to proteasome inhibitors in multiple myeloma based on the FDA Adverse Event Reporting System (FAERS), providing references for rational clinical medication.

Methods

AE data related to multiple myeloma proteasome inhibitors were collected from the FAERS from the first quarter of 2010 to the first quarter of 2024. Signal mining of AEs was conducted using the reporting odds ratio method and Bayesian confidence propagation neural network method.

Results

A total of 8,805 reports for bortezomib, 5,264 for carfilzomib, and 8,771 for ixazomib were collected, with corresponding AE signals of 474, 279, and 287, respectively, involving 23, 21, and 22 System Organ Classes (SOCs). The report information for the three drugs tended to be consistent: more cases were reported in males than in females; the majority of patients were 65 years and over; AEs mostly occurred within 6 months of medication; the outcomes primarily consisted of hospitalization, prolonged hospital stay, and other serious adverse events; the primary reporting country was the United States. The most affected SOCs were infections and infestations, general disorders and administration site conditions, and blood and lymphatic system disorders.

Conclusion

The overall distribution of AEs for the three multiple myeloma proteasome inhibitors was consistent, but there were certain differences in specific AE signal characteristics, which should be noted in clinical applications.

Neutrophil activation biomarker pentraxin 3 for diagnosis and monitoring of macrophage activation syndrome occurrence in adult-onset Still's disease

Macrophage activation syndrome (MAS) is a potentially fatal consequence of adult-onset Still's disease (AOSD), driven by a cytokine storm. Efficient early diagnosis of AOSD-associated MAS requires a sensitive and specific biomarker. In this study, we demonstrated that pentraxin 3 (PTX3), an acute phase protein, was associated with AOSD disease activity and served as a biomarker for AOSD-MAS. PTX3 levels were significantly increased in AOSD patients compared to other autoimmune diseases and healthy controls. Plasma PTX3 levels showed positive correlations with inflammatory markers, the systemic score and the HScore. In active AOSD with MAS, PTX3 levels were higher compared to those in non-AOSD haemophagocytic lymphohistiocytosis (HLH) patients. Moreover, the PTX3's area under the curve value for distinguishing AOSD with MAS exceeded that of soluble interleukin-2 receptor, ferritin and C-reactive protein. Furthermore, plasma levels of PTX3 were associated with circulating NET-DNA levels. To fully understand the underlying mechanism of PTX3 prompting AOSD and AOSD-MAS progression, we discovered that neutrophils exhibited enhanced NET formation and mitogen-activated protein kinases (MAPK) pathway activation upon PTX3 stimulation. More importantly, PTX3-induced NET formation was effectively dampened by MAPK pathway inhibitors. These findings collectively revealed that PTX3 has a favorable correlation with disease activity and may serve as a potential biomarker to differentiate AOSD patients with MAS. Additionally, PTX3 induces NET release via the MAPK pathway, suggesting a pathogenic role in AOSD-MAS.

RNA m6A methylation modulates airway inflammation in allergic asthma via PTX3-dependent macrophage homeostasis

N6-methyladenosine (m6A), the most prevalent mRNA modification, has an important function in diverse biological processes. However, the involvement of m6A in allergic asthma and macrophage homeostasis remains largely unknown. Here we show that m6A methyltransferases METTL3 is expressed at a low level in monocyte-derived macrophages from childhood allergic asthma patients. Conditional knockout of Mettl3 in myeloid cells enhances Th2 cell response and aggravates allergic airway inflammation by facilitating M2 macrophage activation. Loss and gain functional studies confirm that METTL3 suppresses M2 macrophage activation partly through PI3K/AKT and JAK/STAT6 signaling. Mechanistically, m6A-sequencing shows that loss of METTL3 impairs the m6A-YTHDF3-dependent degradation of PTX3 mRNA, while higher PTX3 expression positively correlates with asthma severity through promoting M2 macrophage activation. Furthermore, the METTL3/YTHDF3-m6A/PTX3 interactions contribute to autophagy maturation in macrophages by modulating STX17 expression. Collectively, this study highlights the function of m6A in regulating macrophage homeostasis and identifies potential targets in controlling allergic asthma.

Stem cell-derived hepatocyte therapy using versatile biomimetic nanozyme incorporated nanofiber-reinforced decellularized extracellular matrix hydrogels for the treatment of acute liver failure

Reactive oxygen species (ROS)-associated oxidative stress, inflammation storm, and massive hepatocyte necrosis are the typical manifestations of acute liver failure (ALF), therefore specific therapeutic interventions are essential for the devastating disease. Here, we developed a platform consisting of versatile biomimetic copper oxide nanozymes (Cu NZs)-loaded PLGA nanofibers (Cu NZs@PLGA nanofibers) and decellularized extracellular matrix (dECM) hydrogels for delivery of human adipose-derived mesenchymal stem/stromal cells-derived hepatocyte-like cells (hADMSCs-derived HLCs) (HLCs/Cu NZs@fiber/dECM). Cu NZs@PLGA nanofibers could conspicuously scavenge excessive ROS at the early stage of ALF, and reduce the massive accumulation of pro-inflammatory cytokines, herein efficiently preventing the deterioration of hepatocytes necrosis. Moreover, Cu NZs@PLGA nanofibers also exhibited a cytoprotection effect on the transplanted HLCs. Meanwhile, HLCs with hepatic-specific biofunctions and anti-inflammatory activity acted as a promising alternative cell source for ALF therapy. The dECM hydrogels further provided the desirable 3D environment and favorably improved the hepatic functions of HLCs. In addition, the pro-angiogenesis activity of Cu NZs@PLGA nanofibers also facilitated the integration of the whole implant with the host liver. Hence, HLCs/Cu NZs@fiber/dECM performed excellent synergistic therapeutic efficacy on ALF mice. This strategy using Cu NZs@PLGA nanofiber-reinforced dECM hydrogels for HLCs in situ delivery is a promising approach for ALF therapy and shows great potential for clinical translation.

Efficacy, safety, and biomarker analysis of nivolumab in combination with abemaciclib plus endocrine therapy in patients with HR-positive HER2-negative metastatic breast cancer: a phase II study (WJOG11418B NEWFLAME trial)

BACKGROUND

Hormone receptor (HR)-positive breast cancer is a disease for which no immune checkpoint inhibitors have shown promise as effective therapies. Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors synergistically increased the effectiveness of antiprogrammed cell death protein-1 (anti-PD-1)/programmed death-ligand 1 (PD-L1) antibodies in preclinical studies.

METHODS

This non-randomized, multicohort, phase II study evaluated the efficacy and safety of the anti-PD-1 antibody nivolumab 240 mg administered every 2 weeks in combination with the CDK4/6 inhibitor abemaciclib 150 mg twice daily and either fulvestrant (FUL) or letrozole (LET) as a first-line or second-line treatment for HR-positive HER2-negative metastatic breast cancer. The primary end point was the objective response rate (ORR), and secondary end points were toxicity, progression-free survival, and overall survival. Blood, tissue, and fecal samples were collected at multiple points for correlative studies to evaluate immunity biomarkers.

RESULTS

From June 2019 to early study termination due to safety concerns on July 2020, 17 patients were enrolled (FUL: n=12, LET: n=5). One patient with a prior treatment history in the FUL cohort was excluded. ORRs were 54.5% (6/11) and 40.0% (2/5) in the FUL and LET cohorts, respectively. Treatment-emergent (TE) adverse events (AEs) of grade ≥3 occurred in 11 (92%) and 5 (100%) patients in the FUL and LET cohorts, respectively. The most common grade ≥3 TEAEs were neutropenia (7 (58.3%) and 3 (60.0%) in the FUL and LET cohorts, respectively), followed by alanine aminotransferase elevation (5 (41.6%) and 4 (80.0%)). One treatment-related death from interstitial lung disease occurred in the LET cohort. Ten patients developed liver-related grade ≥3 AEs. Liver biopsy specimens from 3 patients showed hepatitis characterized by focal necrosis with predominant CD8+ lymphocyte infiltration. Marked elevation of tumor necrosis factor-related cytokines and interleukin-11, and a decrease in peripheral regulatory T cells (Tregs), were observed in patients with hepatotoxicity. These findings suggest that treatment-related toxicities were immune-related AEs likely caused by proinflammatory cytokine production and suppression of Treg proliferation due to the addition of abemaciclib to nivolumab therapy.

CONCLUSIONS

Although the combination of nivolumab and abemaciclib was active, it caused severe and prolonged immune-related AEs.

TRIAL REGISTRATION NUMBER

JapicCTI-194782, jRCT2080224706, UMIN000036970.

Integrative Analysis of Transcriptome and Metabolome to Illuminate the Protective Effects of Didymin against Acute Hepatic Injury

Based on the multiomics analysis, this study is aimed at investigating the underlying mechanism of didymin against acute liver injury (ALI). The mice were administrated with didymin for 2 weeks, followed by injection with lipopolysaccharide (LPS) plus D-galactosamine (D-Gal) to induce ALI. The pathological examination revealed that didymin significantly ameliorated LPS/D-Gal-induced hepatic damage. Also, it markedly reduced proinflammatory cytokines release by inhibiting the TLR4/NF-κB pathway activation, alleviating inflammatory injury. A transcriptome analysis proved 2680 differently expressed genes (DEGs) between the model and didymin groups and suggested that the PI3K/Akt and metabolic pathways might be the most relevant targets. Meanwhile, the metabolome analysis revealed 67 differently expressed metabolites (DEMs) between the didymin and model groups that were mainly clustered into the glycerophospholipid metabolism, which was consistent with the transcriptome study. Importantly, a comprehensive analysis of both the omics indicated a strong correlation between the DEGs and DEMs, and an in-depth study demonstrated that didymin alleviated metabolic disorder and hepatocyte injury likely by inhibiting the glycerophospholipid metabolism pathway through the regulation of PLA2G4B, LPCAT3, and CEPT1 expression. In conclusion, this study demonstrates that didymin can ameliorate LPS/D-Gal-induced ALI by inhibiting the glycerophospholipid metabolism and PI3K/Akt and TLR4/NF-κB pathways.

Krill oil prevents lipopolysaccharide-evoked acute liver injury in mice through inhibition of oxidative stress and inflammation

Acute liver injury is a life-threatening syndrome that often results from the actions of viruses, drugs and toxins. Herein, the protective effect and potential mechanism of krill oil (KO), a novel natural product rich in long-chain n-3 polyunsaturated fatty acids bound to phospholipids and astaxanthin, on lipopolysaccharide (LPS)-evoked acute liver injury in mice were investigated. Male C57BL/6J mice were administered intragastrically with 400 mg kg^-1 KO or fish oil (FO) once per day for 28 consecutive days prior to LPS exposure (10 mg kg^-1, intraperitoneally injected). The results revealed that KO pretreatment significantly ameliorated LPS-evoked hepatic dysfunction indicated by reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and attenuated hepatic histopathological damage. KO pretreatment also mitigated LPS-induced hepatic oxidative stress, as evidenced by decreased malondialdehyde (MDA) contents, elevated glutathione (GSH) levels, and elevated catalase (CAT) and superoxide dismutase (SOD) activities. Additionally, LPS-evoked overproduction of pro-inflammatory mediators in serum and the liver was inhibited by KO pretreatment. Furthermore, KO pretreatment suppressed LPS-induced activation of the hepatic toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB)/NOD-like receptor family pyrin domain containing 3 (NLRP3) signaling pathway. Interestingly, the hepatoprotective effect of KO was superior to that of FO. Collectively, the current findings suggest that KO protects against LPS-evoked acute liver injury via inhibition of oxidative stress and inflammation.

Paramylon from Euglena gracilis Prevents Lipopolysaccharide-Induced Acute Liver Injury

Acute liver injury (ALI) is a life-threatening syndrome with high mortality and lacks effective therapies. Rodents under LPS (lipopolysaccharide)/D-Gal (D-galactosamine) stress mimic ALI by presenting dramatically increased inflammation and cell death in the liver. Euglena gracilis, functioning like dietary fiber, is commonly used as a paramylon (Pa)-rich nutritional supplement that has various biological effects such as regulating immune system, anti-obesity, and anti-tumor. Here, we found that Pa or sonicated and alkalized paramylon (SA-Pa) alleviated the LPS/D-Gal-induced hepatic histopathological abnormalities in mice. Compared with Pa, SA-Pa had lower molecular weights/sizes and showed better efficacy in alleviating injury-induced hepatic functions, as well as the transcriptional levels of inflammatory cytokines. Moreover, SA-Pa treatment promoted M2 macrophage activation that enhanced the anti-inflammatory function in the liver, and downregulated STAT3 target genes, such as Fos, Jun, and Socs3 upon the injury. Meanwhile, SA-Pa treatment also alleviated apoptosis and necroptosis caused by the injury. Our results demonstrated that SA-Pa efficiently protected the liver from LPS/D-Gal-induced ALI by alleviating inflammation and cell death.

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.

TLR2 inhibition ameliorates the amplification effect of LPS on lipid accumulation and lipotoxicity in hepatic cells

Background

Gut microbiome dysbiosis is related to the pathogenesis of nonalcoholic fatty liver disease (NAFLD), and the role of toll-like receptor 2 (TLR2) in its molecular mechanism is controversial. Here, we investigated the effects and mechanisms of Escherichia coli-derived lipopolysaccharide (LPS) on lipid accumulation and lipotoxicity in palmitic acid (PA)-treated L02 cell as an NAFLD cell model, and the role of TLR2 in this process.

Methods

Oil red O staining assay and free fatty acid (FFA) content test were performed to determine the effects of LPS on lipid accumulation in a PA-induced NAFLD cell model with or without TLR2 inhibition. The levels of IL-6 and TNF-α were measured to investigate inflammation conditions. Hoechst 33342 staining assay and Caspase-3 activity assay were used to test cell apoptosis, and the expression levels of proteins in the IRS1/PI3K/AKT signaling pathway, TLR2/MyD88/IKKα/NF-κB signaling pathway, and mitochondrion-dependent apoptotic signaling pathway were detected using Western blot.

Results

Lipid accumulation, pro-inflammatory cytokine release, and cell apoptosis with high levels were observed in the PA-induced NAFLD cell model, and LPS aggravated these processes. Whereas TLR2 inhibition could significantly ameliorate PA-induced and LPS-amplified lipid accumulation, inflammatory, and cell apoptosis, it had no significant effect on L02 cells treated with LPS alone.

Conclusions

These results were confirmed by activation or inhibition of the IRS1/PI3K/AKT signaling pathway, TLR2/MyD88/IKKα/NF-κB signaling pathway, and mitochondrion-dependent apoptotic signaling pathway, and were reflected by changes on their proteins expression. TLR2 is involved in PA-induced lipid accumulation and lipotoxicity in L02 cells, which could be aggravated by LPS, although LPS-induced amplification might not be through direct interaction with TLR2.

Effluent Molecular Analysis Guides Liver Graft Allocation to Clinical Hypothermic Oxygenated Machine Perfusion

Hypothermic-oxygenated-machine-perfusion (HOPE) allows assessment/reconditioning of livers procured from high-risk donors before transplantation. Graft referral to HOPE mostly depends on surgeons' subjective judgment, as objective criteria are still insufficient. We investigated whether analysis of effluent fluids collected upon organ flush during static-cold-storage can improve selection criteria for HOPE utilization. Effluents were analyzed to determine cytolysis enzymes, metabolites, inflammation-related mediators, and damage-associated-molecular-patterns. Molecular profiles were assessed by unsupervised cluster analysis. Differences between "machine perfusion (MP)-yes" vs. "MP-no"; "brain-death (DBD) vs. donation-after-circulatory-death (DCD)"; "early-allograft-dysfunction (EAD)-yes" vs. "EAD-no" groups, as well as correlation between effluent variables and transplantation outcome, were investigated. Livers assigned to HOPE (n = 18) showed a different molecular profile relative to grafts transplanted without this procedure (n = 21, p = 0.021). Increases in the inflammatory mediators PTX3 (p = 0.048), CXCL8/IL-8 (p = 0.017), TNF-α (p = 0.038), and ANGPTL4 (p = 0.010) were observed, whereas the anti-inflammatory cytokine IL-10 was reduced (p = 0.007). Peculiar inflammation, cell death, and coagulation signatures were observed in fluids collected from DCD livers compared to those from DBD grafts. AST (p = 0.034), ALT (p = 0.047), and LDH (p = 0.047) were higher in the "EAD-yes" compared to the "EAD-no" group. Cytolysis markers and hyaluronan correlated with recipient creatinine, AST, and ICU stay. The study demonstrates that effluent molecular analysis can provide directions about the use of HOPE.

Lactobacillus casei relieves liver injury by regulating immunity and suppression of the enterogenic endotoxin-induced inflammatory response in rats cotreated with alcohol and iron

Excessive alcohol and iron intake can reportedly cause liver damage. In the present study, we investigated the effect of Lactobacillus casei on liver injury in rats co-exposed to alcohol and iron and evaluated its possible mechanism. Sixty male Wistar rats were randomly divided into three groups for 12 weeks: the Control group (administered normal saline by gavage and provided a normal diet); alcohol +iron group (Model group, treated with alcohol [3.5-5.3 g/kg/day] by gavage and dietary iron [1,500 mg/kg]); Model group supplemented with L. casei (8 × 108 CFU kg-1 day-1) (L. casei group). Using hematoxylin and eosin (HE) staining and transmission electron microscopy, we observed that L. casei supplementation could alleviate disorders associated with lipid metabolism, inflammation, and intestinal mucosal barrier injury. Moreover, levels of serum alanine aminotransferase, gamma-glutamyl transferase, triglyceride (TG), and hepatic TG were significantly increased in the model group; however, these levels were significantly decreased following the 12-week L. casei supplementation. In addition, we observed notable improvements in intestinal mucosal barrier function and alterations in T lymphocyte subsets and natural killer cells in L. casei-treated rats when compared with the model group. Furthermore, L. casei intervention alleviated serum levels of tumor necrosis factor-α and interleukin-1β, accompanied by decreased serum endotoxin levels and downregulated expression of toll-like receptor 4 and its related molecules MyD88, nuclear factor kappa-B p65, and TNF-α. Accordingly, supplementation with L. casei could effectively improve liver injury induced by the synergistic interaction between alcohol and iron. The underlying mechanism for this improvement may be related to immune regulation and inhibition of enterogenic endotoxin-mediated inflammation.

Pattern recognition receptors in health and diseases

Pattern recognition receptors (PRRs) are a class of receptors that can directly recognize the specific molecular structures on the surface of pathogens, apoptotic host cells, and damaged senescent cells. PRRs bridge nonspecific immunity and specific immunity. Through the recognition and binding of ligands, PRRs can produce nonspecific anti-infection, antitumor, and other immunoprotective effects. Most PRRs in the innate immune system of vertebrates can be classified into the following five types based on protein domain homology: Toll-like receptors (TLRs), nucleotide oligomerization domain (NOD)-like receptors (NLRs), retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), C-type lectin receptors (CLRs), and absent in melanoma-2 (AIM2)-like receptors (ALRs). PRRs are basically composed of ligand recognition domains, intermediate domains, and effector domains. PRRs recognize and bind their respective ligands and recruit adaptor molecules with the same structure through their effector domains, initiating downstream signaling pathways to exert effects. In recent years, the increased researches on the recognition and binding of PRRs and their ligands have greatly promoted the understanding of different PRRs signaling pathways and provided ideas for the treatment of immune-related diseases and even tumors. This review describes in detail the history, the structural characteristics, ligand recognition mechanism, the signaling pathway, the related disease, new drugs in clinical trials and clinical therapy of different types of PRRs, and discusses the significance of the research on pattern recognition mechanism for the treatment of PRR-related diseases.

Programmed Death Ligand 1 Is Overexpressed in Liver Macrophages in Chronic Liver Diseases, and Its Blockade Improves the Antibacterial Activity Against Infections

BACKGROUND AND AIMS

Bacterial infections are common and severe in cirrhosis, but their pathogenesis is poorly understood. Dysfunction of liver macrophages may play a role, but information about their function in cirrhosis is limited. Our aims were to investigate the specific profile and function of liver macrophages in cirrhosis and their contribution to infections. Macrophages from human cirrhotic livers were characterized phenotypically by transcriptome analysis and flow cytometry; function was assessed in vivo by single photon emission computerized tomography in patients with cirrhosis. Serum levels of specific proteins and expression in peripheral monocytes were determined by ELISA and flow cytometry. In vivo phagocytic activity of liver macrophages was measured by spinning disk intravital microscopy in a mouse model of chronic liver injury.

APPROACH AND RESULTS

Liver macrophages from patients with cirrhosis overexpressed proteins related to immune exhaustion, such as programmed death ligand 1 (PD-L1), macrophage receptor with collagenous structure (MARCO), and CD163. In vivo phagocytic activity of liver macrophages in patients with cirrhosis was markedly impaired. Monocytes from patients with cirrhosis showed overexpression of PD-L1 that paralleled disease severity, correlated with its serum levels, and was associated with increased risk of infections. Blockade of PD-L1 with anti-PD-L1 antibody caused a shift in macrophage phenotype toward a less immunosuppressive profile, restored liver macrophage in vivo phagocytic activity, and reduced bacterial dissemination.

CONCLUSION

Liver cirrhosis is characterized by a remarkable impairment of phagocytic function of macrophages associated with an immunosuppressive transcriptome profile. The programmed cell death receptor 1/PD-L1 axis plays a major role in the impaired activity of liver macrophages. PD-L1 blockade reverses the immune suppressive profile and increases antimicrobial activity of liver macrophages in cirrhosis.

Lipopolysaccharide/D-galactosamine-induced acute liver injury could be attenuated by dopamine receptor agonist rotigotine via regulating NF-κB signaling pathway

The pathological of lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced acute liver injury is similar to what is seen clinically, and be mediated by the release of pro-inflammatory mediators. A growing body of studies have shown that dopamine (DA) and DA receptor agonist are associated with inflammation and immune response. Rotigotine, a non-ergoline dopamine receptor agonist, is a drug for the treatment of Parkinson's disease. Rotigotine-loaded microspheres (RoMS) is an intramuscular extended-release agent, which can steadily release rotigotine for more than 7 days after a single administration. The present study aimed to investigate the effects of rotigotine and RoMS on inflammation and acute liver injury induced by LPS/D-Gal in mice. The LPS/D-Gal-induced liver injury was evidenced by increases of serum aminotransferases activities and liver histological lesions. Pretreatment with rotigotine or RoMS not only ameliorated the liver histologic lesions, but also reduced the activities of serum aminotransferases and the production of TNF-α. It also showed that rotigotine and RoMS increased DA receptor 2 (DRD2) expression in LPS/D-Gal-exposed mice. Rotigotine and RoMS activated β-arrestin 2, inhibited the phosphorylation of Akt, IκB and the transposition of NF-κB. In line with the above findings, the protective effects of rotigotine and RoMS were abrogated by haloperidol, a DA receptor antagonist. In conclusion, dopamine receptor agonist can regulate NF-κB inflammatory signaling pathway and exert protective effects in LPS/D-Gal-induced liver injury.

Excesive consumption of unsaturated fatty acids leads to oxidative and inflammatory instability in Wistar rats

Lifestyle modifications such as increase in high-fat food consumption importantly increases the risks for cardiovascular disease. The principal objective of this study is to analyze effects of different high fat diet (HFD) sources on haemodynamic parameters, lipid and oxidative profile, myeloperoxidase activity, and markers of inflammation (IL-6/pentraxin-3). HFD containing 20% of fat, provided by lard (saturated) or soybean oil (unsaturated), as well as control diet were administering to three groups (L, SO and C). Food efficiency ratio and plasma lipids were significantly elevated in both HFD groups. However, only SO group showed an increase in systolic arterial pressure, oxidative stress index, myeloperoxidase activity, liver lipids as well as markers of inflammation: IL-6 and pentraxin-3 (PTX3). In summary, these results indicate inflammogenic potential of excessive soybean oil consumption in triggering liver damage.

Pb Toxicity on Gut Physiology and Microbiota

Lead (Pb) is a toxic heavy metal, having profound threats to the global population. Multiple organs such as kidney, and liver, as well as nervous, hematologic, and reproductive systems, are commonly considered the targets of Pb toxicity. Increasing researches reported that the effects of Pb on gastrointestinal tracts are equally intensive, especially on intestinal microbiota. This review summarized Pb toxicity on gut physiology and microbiota in different animal models and in humans, of which the alterations may further have effects on other organs in host. To be more specific, Pb can impair gut barrier and increase gut permeability, which make inflammatory cytokines, immunologic factors, as well as microbial metabolites such as bile acids (BA) and short-chain fatty acids (SCFAs) enter the enterohepatic circulation easily, and finally induce multiple systematic lesion. In addition, we emphasized that probiotic treatment may be one of the feasible and effective strategies for preventing Pb toxicity.

Elevated Serum Pentraxin-3 Levels is Positively Correlated to Disease Severity and Coagulopathy in COVID-19 Patients

BACKGROUND

Coronavirus disease 2019 (COVID-19) is highly contagious and deadly and is associated with coagulopathy. Pentraxin-3(PTX3) participates in innate resistance to infections and plays a role in thrombogenesis.

PURPOSE

The present study aimed to investigate the role of PTX3 in coagulopathy in patients with COVID-19.

METHODS

A retrospective study, including thirty-nine COVID-19 patients, enrolled in Hunan, China, were performed. The patients were classified into the D-dimer_L (D-dimer <1mg/L) and D-dimer_H (D-dimer≥1mg/L) groups basing on the plasma D-dimer levels on admission. Serum PTX3 levels were detected by enzyme-linked immunosorbent assays and compared between those two groups, then receiver operating characteristic (ROC) curve analysis, correlation analysis, and linear regression models were performed to analyze the association between PTX3 and D-dimer.

RESULTS

Our results showed that serum PTX3 levels (median values, 10.21 vs. 3.36, P<0.001), computerized chest tomography (C.T.) scores (median values, 10.0 vs. 9.0, P<0.05), and length of stay (LOS) (mean values, 16.0 vs. 10.7, P=0.001) in the D-dimer_H group were significantly higher than that in D-dimer_L group. ROC curve analysis revealed that the AUC of white blood corpuscle counts, C-reaction protein, erythrocyte sedimentation rate, and PTX3 for COVID-19 were 0.685, 0.863, 0.846, and 0.985, respectively. Correlation analysis showed that there was a positive relationship between PTX3 and D-dimer (r=0.721, P<0.001), chest CT imaging score (r=0.418, P=0.008), and LOS (r=0.486, P=0.002). Multiple linear regression analysis showed that the coefficient of determination was 0.657 (P < 0.001).

CONCLUSION

Serum level of PTX3 was positively correlated with disease severity and coagulopathy. Detection of serum PTX3 level could help identify severer patients on admission and may be a potential therapeutic target for coagulopathy in patients with COVID-19.

Serum pentraxin 3 as a biomarker of hepatocellular carcinoma in chronic hepatitis B virus infection

Biomarkers for early diagnosis of hepatocellular carcinoma (HCC) are needed in chronic hepatitis B virus (HBV) infection, a leading cause of HCC. We evaluated whether measurement of serum pentraxin 3 (PTX3) could improve diagnosis of HCC in chronic HBV infection. Data from patients with HBV-related chronic hepatitis (n = 159), cirrhosis (n = 99) and HCC (n = 107), and healthy controls (n = 151) were analyzed. Serum PTX3 concentration was measured by immunoassay. Area under the receiver operating characteristic curve (AUC) was applied to assess diagnostic accuracy. PTX3 levels were significantly higher in HBV patients than in healthy controls (P < 0.001) and in HCC than in chronic hepatitis (P < 0.001) or cirrhosis patients (P < 0.001). PTX3 was an independent risk factor of HCC [odds ratio (OR) 1.617, P < 0.001] and could distinguish HCC in chronic HBV infection [cutoff 9.231 ng/mL, AUC 0.929 with 95% confidence interval (CI) of 0.898-0.953], including α-fetoprotein (AFP) negative [cutoff 8.985 ng/mL, AUC (95%CI) 0.947 (0.908-0.973)] and early-stage HCC [cutoff 9.359 ng/mL, AUC (95%CI) 0.920 (0.885-0.947)]. Combination of PTX3 with AFP improved the discrimination of early HCC from chronic HBV infection [AUC (95%CI) 0.948 (0.918-0.970)]. In short, PTX3 measurement could identify HCC, including AFP-negative and early-stage HCC, in chronic HBV infection.

[Research progress on the role of pentraxin 3 in polycystic ovary syndrome]

Polycystic ovary syndrome (PCOS) is a common endocrine disease of child-bearing period women and one of the main causes of infertility in women. Pentraxin 3 (PTX3) is a multifunctional protein with a series of biological activities. PTX3 participates in the regulation of insulin secretion and glucose metabolism, ovarian cumulus cell function, inflammatory factor activity, androgen metabolism, lipid absorption and transport, and endothelial cell function, thereby improving insulin resistance, promoting follicular development and ovulation, reducing chronic inflammation, inhibiting androgen levels, improving lipid metabolism abnormalities and preventing atherosclerosis and cardiovascular diseases, thus participating in the occurrence of PCOS and its complications. This article reviews the mechanism of PTX3 in PCOS and its complications, trying to provide new ideas and directions for the study of PCOS pathogenesis and its clinical diagnosis and treatment.

Chemerin-156 is the Active Isoform in Human Hepatic Stellate Cells

The chemokine chemerin exists as C-terminally processed isoforms whose biological functions are mostly unknown. A highly active human chemerin variant (huChem-157) was protective in experimental hepatocellular carcinoma (HCC) models. Hepatic stellate cells (HSCs) are central mediators of hepatic fibrogenesis and carcinogenesis and express the chemerin receptors chemokine-like receptor 1 (CMKLR1) and G protein-coupled receptor 1 (GPR1). Here we aimed to analyse the effect of chemerin isoforms on the viability, proliferation and secretome of the human HSC cell line LX-2. Therefore, huChem-157, 156 and 155 were over-expressed in LX-2 cells, which have low endogenous chemerin levels. HuChem-157 produced in LX-2 cells activated CMKLR1 and GPR1, and huChem-156 modestly induced GPR1 signaling. HuChem-155 is an inactive chemerin variant. Chemerin isoforms had no effect on cell viability and proliferation. Cellular expression of the fibrotic proteins galectin-3 and alpha-smooth muscle actin was not regulated by any chemerin isoform. HuChem-156 increased IL-6, IL-8 and galectin-3 in cell media. HuChem-157 was ineffective, and accordingly, did not enhance levels of these proteins in media of primary human hepatic stellate cells when added exogenously. These analyses provide evidence that huChem-156 is the biologic active chemerin variant in hepatic stellate cells and acts as a pro-inflammatory factor.

Pentraxin 3 promotes airway inflammation in experimental asthma

Background

Pentraxin 3 (PTX3) regulates multiple aspects of innate immunity and tissue inflammation. Recently, it has been reported that PTX3 deficiency enhances interleukin (IL)-17A–dominant pulmonary inflammation in an ovalbumin (OVA)-induced mouse asthma model. However, whether PTX3 treatment would provide protection against allergic airway inflammation has not been clearly elucidated. The goal of this study was to further investigate the effect of recombinant PTX3 administration on the phenotype of asthma.

Methods

C57BL/6 J mice were sensitized and challenged with OVA to induce eosinophilic asthma model, as well as sensitized with OVA plus LPS and challenged with OVA to induce neutrophilic asthma model. We evaluated effect of recombinant PTX3 on asthma phenotype through both asthma models. The bronchoalveolar lavage fluid (BALF) inflammatory cells and cytokines, airway hyperresponsiveness, and pathological alterations of the lung tissues were assessed.

Results

In both eosinophilic and neutrophilic asthma models, PTX3 treatment provoked airway hyperresponsiveness, concomitant with increased inflammatory cytokines IL-4, IL-17, eotaxin, and transforming growth factor (TGF)-β1 and aggravated airway accumulation of inflammatory cells, especially eosinophils and neutrophils. In histological analysis of the lung tissue, administration of PTX3 promoted inflammatory cells infiltration, mucus production, and collagen deposition. In addition, PTX3 also significantly enhanced STAT3 phosphorylation in lung tissue.

Conclusion

Our results show that exogenous PTX3 can exacerbate multiple asthmatic features by promoting both eosinophils and neutrophils lung infiltration and provide new evidence to better understand the complex role of PTX3 in allergic airway inflammation.

Pentraxin 3 inhibits fibroblast growth factor 2 induced osteoclastogenesis in rheumatoid arthritis

BACKGROUND

Synovial fibroblasts (SFs) act as key effector cells mediating synovial inflammation and joint destruction in rheumatoid arthritis (RA). Fibroblast growth factor 2 (FGF2) and its receptors (FGFRs) play important roles in RASF-mediated osteoclastogenesis. Pentraxin 3 (PTX3) is a soluble pattern recognition receptor with nonredundant roles in inflammation and innate immunity. PTX3 is produced by various cell types, including SFs and is highly expressed in RA. However, the role of PTX3 in FGF2-induced osteoclastogenesis in RA and the underlying mechanism have been poorly elucidated.

METHODS

We first determined the expression of FGF2 and RANKL in synovial tissue and synovial fluid of RA patients. We then examined the effect of PTX3 on RASF osteoclastogenesis induced by endogenous and exogenous FGF2 in isolated RASF cells treated with FGF2 and/or recombinant PTX3 (rPTX3). Thirdly, we analyzed the effect of PTX3 on FGF2 binding to FGFR-1 and HSPG receptors on RASFs. Lastly, we evaluated joint morphology after injection of rPTX3 into collagen-induced arthritis (CIA) mice.

RESULTS

FGF2 was confirmed to be highly expressed in both synovial tissue and synovial fluid of RA patients. FGF2 promoted cell proliferation and increased the expressions of RANKL and ICAM-1 and RANKL/OPG to induce osteoclastogenesis in RASF, while anti-FGF2 neutralized this effect. PTX3 significantly inhibited FGF2-induced RASF cell growth and osteoclastogenesis by preventing the interaction of ¹²⁵I-FGF2 and FGFRs on the same cells. In addition, administration of rPTX3 significantly ameliorated cartilage and bone destruction in mice with CIA.

CONCLUSIONS

PTX3 exhibited an inhibitory effect on the autocrine and paracrine stimulation of FGF2 on SFs, and ameliorated bone destruction in CIA mice. PTX3 may be implicated in bone destruction in RA, which may provide theoretical evidence and potential therapeutic targets for RA treatment.

Sleep deprivation aggravated lipopolysaccharide/D-galactosamine-induced acute liver injury by suppressing melatonin production

OBJECTIVE

Sleep loss is common in patients with liver injury, but the effects of sleep deprivation (SD) on liver injury remain unclear. In the present study, the potential effects of SD on acute liver injury and the underlying mechanisms have been investigated.

METHODS

The sleep of male BALB/c mice has been deprived by using a modified multiple platform water bath for 3 days and acute liver injury was induced by intraperitoneal injection of lipopolysaccharide (LPS) and D-galactosamine (D-Gal). The degree of liver injury was detected by aminotransferase determination, histopathology and survival rate analysis. Inflammatory response and melatonin (MT) were measured by enzyme-linked immunosorbent assay (ELISA). In addition, hepatocyte apoptosis was determined by caspase activity measurement and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay.

RESULTS

We observed that SD increased plasma aminotransferases, TUNEL-positive hepatocytes, histological abnormalities and mortality rates in mice with LPS/D-Gal treatment. SD also promoted LPS/D-Gal-induced production of TNF-α and upregulated hepatic caspase-8, caspase-9, and caspase-3 activities in LPS/D-Gal-exposed mice. In addition, SD significantly decreased MT contents in plasma of mice with acute liver injury, but supplementation with MT reversed these SD-promoted changes.

CONCLUSION

Our data suggested that SD exacerbated LPS/D-Gal-induced liver injury via decreasing melatonin production.

cis-4-[18F]fluoro-L-proline Molecular Imaging Experimental Liver Fibrosis

Introduction: Early-stage liver fibrosis is potentially reversible, but difficult to diagnose. Clinical management would be enhanced by the development of a non-invasive imaging technique able to identify hepatic injury early, before end-stage fibrosis ensues. The analog of the amino acid proline, cis-4-[¹⁸F]fluoro-L-proline ([¹⁸F]fluoro-proline), which targets collagenogenesis in hepatic stellate cells (HSC), was used to detect fibrosis.

Methods: Acute steatohepatitis was induced in experimental animals by liquid ethanol diet for 8 weeks, intra-gastric binge feedings every 10th day along with lipopolysaccharide (LPS) injection. The control animals received control diet for 8 weeks and an equivalent volume of saline on the same schedule as the acute steatohepatitis model. First, in vitro cellular experiments were carried out to assess [³H]proline uptake by HSC, hepatocytes and Kupffer cells derived from rats with acute steatohepatitis (n = 14) and controls (n = 14). Next, ex vivo liver experiments were done to investigate unlabeled proline-mediated collagen synthesis and its associated proline transporter expression in acute steatohepatitis (n = 5) and controls (n = 5). Last, in vivo dynamic and static [¹⁸F]fluoro-proline micro-PET/CT imaging was performed in animal models of acute steatohepatitis (n = 7) and control (n = 7) mice.

Results: [³H]proline uptake was 5-fold higher in the HSCs of steatohepatitis rats than controls after incubation of up to 60 min. There was an excellent correlation between [³H]proline uptake and liver collagen expression (r-value > 0.90, p < 0.05). Subsequent liver tissue studies demonstrated 2–3-fold higher proline transporter expression in acute steatohepatitis animals than in controls, and proline-related collagen synthesis was blocked by this transporter inhibitor. In vivo micro-PET/CT studies with [¹⁸F]fluoro-proline showed 2–3-fold higher uptake in the livers of acute steatohepatitis mice than in controls. There was an excellent correlation between [¹⁸F]fluoro-proline uptake and liver collagen expression in the livers of acute steatohepatitis mice (r-value = 0.97, p < 0.001).

Conclusion: [¹⁸F]fluoro-proline localizes in the liver and correlates with collagenogenesis in acute steatohepatitis with a signal intensity that is sufficiently high to allow imaging with micro-PET/CT. Thus, [¹⁸F]fluoro-proline could serve as a PET imaging biomarker for detecting early-stage liver fibrosis.

Pentraxin-3 is not related to disease severity in cirrhosis and hepatocellular carcinoma patients

The acute-phase protein pentraxin-3 (PTX3) is a component of the innate immune system. Inflammation and tissue injury increased PTX3 in the injured liver, and accordingly, circulating PTX3 was induced in patients with chronic liver diseases. In the present study, PTX3 protein was determined in systemic, hepatic, and portal vein plasma of patients with liver cirrhosis to assess a possible association between hepatic PTX3 release and extent of liver injury. However, PTX3 levels were not related to disease severity. Of note, portal PTX3 levels were higher than concentrations in the hepatic vein. PTX3 in the hepatic and portal veins was negatively correlated with factor V, antithrombin 3, and prothrombin time. PTX3 did neither correlate with C-reactive protein nor galectin-3 or resistin, whereby the latter two proteins are associated with hepatic injury. PTX3 levels were not changed in cirrhosis patients with ascites or varices and did not correlate with the hepatic venous pressure gradient. Likewise, serum PTX3 was not correlated with histological steatosis, inflammation, or fibrosis stage in patients with hepatocellular carcinoma (HCC). Moreover, PTX3 was not associated with tumor node metastasis classification in HCC. Above all, PTX3 increased in hepatic, portal, and systemic blood immediately after transjugular intrahepatic portosystemic shunt (TIPS). Higher PTX3 in portal than hepatic vein plasma and further increase after TIPS suggests that the liver eliminates PTX3 from the circulation. In summary, PTX3 is not of diagnostic value in cirrhosis and HCC patients.

CD5L is a pleiotropic player in liver fibrosis controlling damage, fibrosis and immune cell content

BACKGROUND

Chronic hepatic inflammation leads to liver fibrosis, which may progress to cirrhosis, a condition with high morbidity. Our aim was to assess the as yet unknown role of innate immunity protein CD5L in liver fibrosis.

METHODS

CD5L was measured by ELISA in plasma samples from cirrhotic (n = 63) and hepatitis (n = 39) patients, and healthy controls (n = 7), by immunohistochemistry in cirrhotic tissue (n = 12), and by quantitative RT-PCR in mouse liver cell subsets isolated by cell sorting. Recombinant CD5L (rCD5L) was administered into a murine model of CCl₄-induced fibrosis, and damage, fibrosis and hepatic immune cell infiltration, including the LyC6^hi (pro-fibrotic)-LyC6^low (pro-resolutive) monocyte ratio were determined. Moreover, rCD5L was added into primary human hepatic stellate cells to study transforming growth factor β (TGFβ) activation responses.

FINDINGS

Cirrhotic patients showed elevated plasma CD5L concentrations as compared to patients with hepatitis and healthy controls (Mann-Whitney test p < 0·0001). Moreover, plasma CD5L correlated with disease progression, FIB4 fibrosis score (r:0·25, p < 0·0001) and tissue expression (r = 0·649; p = 0·022). Accordingly, CCl₄-induced damage increased CD5L levels in total liver, particularly in hepatocytes and macrophages. rCD5L administration attenuated CCl₄-induced injury and fibrosis as determined by reduced serum transaminase and collagen content. Moreover, rCD5L inhibited immune cell infiltration and promoted a phenotypic shift in monocytes from LyC6^hi to LyC6^low. Interestingly, rCD5L also had a direct effect on primary human hepatic stellate cells promoting SMAD7 expression, thus repressing TGFβ signalling.

INTERPRETATION

Our study identifies CD5L as a key pleiotropic inhibitor of chronic liver injury. FUND: Fundació Marató TV3, AGAUR and the ISCIII-EDRF.

Pentraxin 3 Detects Clinically Significant Fibrosis in Patients with Chronic Viral Hepatitis C

Pentraxin 3 (PTX3) plays a pathogenic role in experimental models of chronic liver injury and contributes to the progression of fibrosis. The detection of advanced fibrosis (METAVIR F≥3) is important to identify patients who are in urgent need of antiviral treatments versus those whose treatment could be deferred (F≥2). The aim was to assess the diagnostic value of PTX3 as a potential biomarker for clinically significant and advanced fibrosis. PTX3 associations with biochemical and histological parameters of inflammatory activity and fibrosis were investigated in 138 patients with chronic viral hepatitis C (HCV) before antiviral treatment. METAVIR histological scores of activity and fibrosis were obtained. PTX3 was measured by enzyme-linked immunosorbent assay. The diagnostic accuracy of serum PTX3 levels was compared to that of other fibrosis markers, including transforming growth factor‐β₁ (TGF-β₁), hyaluronic acid (HA), aspartate transaminase to platelet ratio index (APRI), fibrosis score based on four factors (FIB4), gamma-glutamyltranspeptidase to platelet ratio (GPR), and the liver stiffness measurement (LSM) by transient elastography (FibroScan®). In HCV patients the PTX3 level increased in parallel with the METAVIR histological score of activity, being independently associated with the METAVIR fibrosis score (P < 0.001). Using the receiver operating characteristics analysis, the best marker for detecting F≥2 and F≥3 was PTX3 with AUC = 0.802 and AUC = 0.867, respectively. The area under the curve of PTX3 for predicting significant fibrosis (F≥2) was significantly greater than those for the GPR ratio (AUC = 0.648) and FIB-4 score (AUC = 0.770) and similar to that for APRI index (AUC = 0.831). PTX3 provided clinically relevant diagnostic accuracy as a single marker of significant fibrosis.

The antagonistic effect of tamoxifen against d-galactosamine/lipopolysaccharide-induced acute liver failure is associated with reactivation of hepatic nuclear factor-κB

Context: Tamoxifen (TAM) ameliorates D-galactosamine/lipopolysaccharide (Gal/LPS)-induced acute liver failure (ALF) through its antioxidative effect; thus, this study was designed to determine whether the effectiveness of TAM is related to nuclear factor-κB (NF-κB) reactivation. Materials and methods: Experimental mice were injected with TAM once daily for 3 consecutive days intraperitoneally (i.p). Twelve hours after pretreatment, Gal/LPS was given to mice (i.p) for ALF induction. In the positive control group, N-acetylcysteine (NAC) was administered immediately after ALF establishment. Except for survival observation, other animals were sacrificed 7 h after Gal/LPS treatment. Survival and hepatic failure were evaluated. For the oxidation assessment, the reduced/oxidized glutathione (GSH/GSSG) ratio and hepatic superoxide dismutase (SOD) activity were analyzed using both colorimetry and Western blotting. Lastly, hepatic NF-κB activation was measured through Western blot analysis of p65 and IκBα. Results: The results indicated that pretreatment with TAM dramatically attenuated Gal/LPS-induced ALF, as demonstrated by improved survival (70%), decreased transaminase levels, and reversed histopathological manifestation. In addition, the hepatic GSH/GSSG ratio and SOD activity were decreased in the ALF model. However, to some degree, TAM and NAC effectively prevented this undesirable phenomenon in contrast to the ALF model. Western blotting revealed that compared with mice in the ALF model group, mice treated with TAM or NAC showed reactivation of hepatic NF-κB. Conclusions: Taking the results together with those of other studies, we conclude that TAM may attenuate Gal/LPS-induced ALF by antagonizing oxidative stress through NF-κB reactivation.

Role of mitophagy regulation by ROS in hepatic stellate cells during acute liver failure

Liver sinusoids serve as the first line of defense against extrahepatic stimuli from the intestinal tract. Hepatic stellate cells (HSCs) are pericytes residing in the perisinusoidal space that integrate cytokine-mediated inflammatory responses in the sinusoids and relay these signals to the liver parenchyma. Oxidative stress has been shown to promote inflammation during acute liver failure (ALF). Whether and how oxidative stress is involved in HSC inflammation during ALF remains unclear. Level of systemic oxidative stress is reflected by superoxide dismutase (SOD). Thus, ALF patients were recruited to investigate the correlation between plasma SOD levels and clinical features. Liver tissues were collected from chronic hepatitis patients by biopsy and from ALF patients who had undergone liver transplantation. SOD2 expression and HSCs activation were investigated by immunohistochemistry. Inflammation, mitophagy, and apoptosis were investigated by immunoblot analysis and flow cytometry in HSCs treated with lipopolysaccharide (LPS) and reactive oxygen species (ROS) donors. The plasma SOD level was significantly increased in patients with ALF compared with those with cirrhosis (444.4 ± 23.58 vs. 170.07 ± 3.52 U/ml, P < 0.01) and was positively correlated with the Model for End-Stage Liver Disease-Na score ( R² = 0.4720, P < 0.01). In vivo observations revealed that SOD2 immunostaining was increased in ALF patients and mice models, and in vitro experiments demonstrated that LPS/ROS promoted inflammation via inhibiting mitophagy. Moreover, the regulation of inflammation was apoptosis independent in HSCs. LPS-induced increases in oxidative stress promote inflammation through inhibiting mitophagy in HSCs during the process of ALF, providing a novel strategy for the treatment of patients with ALF. NEW & NOTEWORTHY Here we demonstrate that the serum superoxide dismutase (SOD) level is significantly increased in patients with acute liver failure (ALF), and, correlated with the Model for End-Stage Liver Disease-Na score, SOD level dropped in the remission stage of ALF. We identify that, in liver tissue from ALF patients and mice models, manganese-dependent SOD was overexpressed, and show lipopolysaccharide/H₂O₂ inhibits mitophagy via reactive oxygen species in hepatic stellate cells (HSCs). We show that inhibited mitophagy promotes inflammation in HSCs, whereas mitophagy inducer rescues HSCs from lipopolysaccharide-induced inflammation.

Emodin Attenuates Lipopolysaccharide-Induced Acute Liver Injury via Inhibiting the TLR4 Signaling Pathway in vitro and in vivo

Aims: Emodin is an anthraquinone with potential anti-inflammatory properties. However, the possible molecular mechanisms and protective effects of emodin are not clear. The objective of this study was to investigate the possible molecular mechanisms and protective effects of emodin on lipopolysaccharide (LPS)-induced acute liver injury (ALI) via the Toll-like receptor 4 (TLR4) signaling pathway in the Raw264.7 cell line and in Balb/c mice. Methods: This study established an inflammatory cellular model and induced an ALI animal model. TLR4 was overexpressed by lentivirus and downregulated by small interfering RNA (siRNA) technology. The mRNA and protein levels of TLR4 and downstream molecules were detected in cells and liver tissue. The tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 levels in supernatant and serum were determined by ELISA. The distribution and expression of mannose receptor C type 1 (CD206) and arginase 1 (ARG1) in the liver were tested by immunofluorescence. Mouse liver function and histopathological observations were assessed. Results: Administration of emodin reduced the protein and/or mRNA levels of TLR4 and its downstream molecules following LPS challenge in Raw264.7 cells and in an animal model. Additionally, emodin suppressed the expression of TNF-α and IL-6 in cell culture supernatant and serum. The inhibitory effect of emodin was also confirmed in RAW264.7 cells, in which TLR4 was overexpressed or knocked down. Additionally, ARG1 and CD206 were elevated in the emodin groups. Emodin also decreased serum ALT and AST levels and alleviated the liver histopathological damage induced by LPS. Conclusion: Emodin showed excellent hepatoprotective effects against LPS-induced ALI, possibly by inhibiting TLR4 signaling pathways.

Generation of Hepatic Stellate Cells from Human Pluripotent Stem Cells Enables In Vitro Modeling of Liver Fibrosis

The development of complex in vitro hepatic systems and artificial liver devices has been hampered by the lack of reliable sources for relevant cell types, such as hepatic stellate cells (HSCs). Here we report efficient differentiation of human pluripotent stem cells into HSC-like cells (iPSC-HSCs). iPSC-HSCs closely resemble primary human HSCs at the transcriptional, cellular, and functional levels and possess a gene expression profile intermediate between that of quiescent and activated HSCs. Functional analyses revealed that iPSC-HSCs accumulate retinyl esters in lipid droplets and are activated in response to mediators of wound healing, similar to their in vivo counterparts. When maintained as 3D spheroids with HepaRG hepatocytes, iPSC-HSCs exhibit a quiescent phenotype but mount a fibrogenic response and secrete pro-collagen in response to known stimuli and hepatocyte toxicity. Thus, this protocol provides a robust in vitro system for studying HSC development, modeling liver fibrosis, and drug toxicity screening.

Pentraxin levels in non-eosinophilic versus eosinophilic asthma

BACKGROUND

Innate immunity has been thought to be involved in asthma pathogenesis. Pentraxins, acting as soluble pattern recognition molecules, play an important role in humoral innate immunity. Asthma is a heterogeneous inflammatory disease of airways and can be classified as eosinophilic or non-eosinophilic asthma.

OBJECTIVE

To investigate whether pentraxin levels differ in subjects with eosinophilic versus non-eosinophilic asthma. Furthermore, to access the predictive performance of pentraxin levels for discriminating asthma inflammatory phenotypes.

METHODS

A total of 80 asthmatic patients and 24 healthy control subjects underwent sputum induction at study inclusion. Differential leucocyte counts were performed on selected sputum. Plasma C-reactive protein (CRP), serum amyloid P (SAP), pentraxin 3 (PTX3), and sputum SAP, PTX3, IL-8 levels were determined by enzyme-linked immunosorbent assay.

RESULTS

Subjects with non-eosinophilic asthma had significantly increased pentraxin levels compared with those with eosinophilic asthma and healthy controls, with median (interquartile range) plasma CRP levels of 0.86 (0.28-2.07), 0.26 (0.14-0.85), and 0.15 (0.09-0.45)mg/L (P < .001), respectively, plasma SAP levels of 33.69 (19.79-58.39), 19.76 (16.11-30.58), and 20.06 (15.68-31.11)mg/L (P = .003), respectively, and sputum PTX3 levels of 4.9 (1.35-18.72), 0.87 (0.30-2.07), and 1.08 (0.31-4.32)ng/mL (P < .001), respectively. Conversely, sputum SAP concentrations of eosinophilic asthmatics (median, 21.49 ng/mL; IQR, 6.86-38.79 ng/mL) were significantly higher than those of non-eosinophilic patients (median, 8.15 ng/mL; IQR, 2.82-18.01 ng/mL) and healthy controls (median, 8.79 ng/mL; IQR, 2.00-16.18 ng/mL). Asthma patients with high plasma CRP (P = .004), SAP (P = .005) and sputum PTX3 levels (P < 0.001) also had significantly lower sputum eosinophil percentages. Sputum PTX3 levels had the best power (11.18-fold, P < .001) to predict non-eosinophilic airway inflammation in asthma patients.

CONCLUSION AND CLINICAL RELEVANCE

Pentraxin levels differed significantly between patients with non-eosinophilic asthma and those with eosinophilic asthma. Furthermore, elevated pentraxin expressions may predict non-eosinophilic airway inflammation in asthmatic patients.

Exploring the Immunomodulatory Moonlighting Activities of Acute Phase Proteins for Tolerogenic Dendritic Cell Generation

The acute phase response is generated by an overwhelming immune-inflammatory process against infection or tissue damage, and represents the initial response of the organism in an attempt to return to homeostasis. It is mediated by acute phase proteins (APPs), an assortment of highly conserved plasma reactants of seemingly different functions that, however, share a common protective role from injury. Recent studies have suggested a crosstalk between several APPs and the mononuclear phagocyte system (MPS) in the resolution of inflammation, to restore tissue integrity and function. In fact, monocyte-derived dendritic cells (Mo-DCs), an integral component of the MPS, play a fundamental role both in the regulation of antigen-specific adaptive responses and in the development of immunologic memory and tolerance, particularly in inflammatory settings. Due to their high plasticity, Mo-DCs can be modeled in vitro toward a tolerogenic phenotype for the treatment of aberrant immune-inflammatory conditions such as autoimmune diseases and allotransplantation, with the phenotypic outcome of these cells depending on the immunomodulatory agent employed. Yet, recent immunotherapy trials have emphasized the drawbacks and challenges facing tolerogenic Mo-DC generation for clinical use, such as reduced therapeutic efficacy and limited in vivo stability of the tolerogenic activity. In this review, we will underline the potential relevance and advantages of APPs for tolerogenic DC production with respect to currently employed immunomodulatory/immunosuppressant compounds. A further understanding of the mechanisms of action underlying the moonlighting immunomodulatory activities exhibited by several APPs over DCs could lead to more efficacious, safe, and stable protocols for precision tolerogenic immunotherapy.

Protective role of puerarin on LPS/D-Gal induced acute liver injury via restoring autophagy

Acute liver injury is a destructive liver disorder resulting from overwhelming liver inflammation, oxidative stress and hepatocyte death. Puerarin is a natural flavonoid compound isolated from the traditional Chinese herb radix puerariae. This study investigated the protective effects of puerarin against lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced liver injury and the potential mechanisms in mice. Mice were given an intraperitoneal administration of puerarin 200 mg/kg 2 h prior to LPS (50 μg/kg)/D-Gal (400 mg/kg) injection and were sacrificed 6 h post LPS/D-Gal treatment. The results showed that administration of puerarin substantially alleviated LPS/D-Gal-induced acute liver injury in mice by increased survival rates, improved liver histopathology, reduced plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, alleviated production of pro-inflammatory cytokines, and suppressed hepatocyte apoptosis. Moreover, puerarin pretreatment activated autophagy by increased the ratio of LC3B-II/I and the protein levels of Beclin-1, decreased the levels of p62 protein expression. Taken together, these findings demonstrated that puerarin could prevent the LPS/D-Gal-induced liver injury in mice, and its mechanisms might be associated with the increments of autophagy and suppression of apoptosis.