The role of the liver in the response to LPS: experimental and clinical findings

Characterization of hepatic inflammatory changes in a C57BL/6J mouse model of alpha1-antitrypsin deficiency

Alpha-1 antitrypsin deficiency (AATD) is a genetic disease caused by a hepatic accumulation of mutant alpha-1 antitrypsin (ZAAT). Individuals with AATD are prone to develop a chronic liver disease that remains undiagnosed until late stage of the disease. Here, we sought to characterize the liver pathophysiology of a human transgenic mouse model for AATD with a manifestation of liver disease compared with normal transgenic mice model. Male and female transgenic mice for normal (Pi*M) and mutant variant (Pi*Z) human alpha-1 antitrypsin at 3 and 6 mo of age were subjected to this study. The progression of hepatic ZAAT accumulation, hepatocyte injury, steatosis, liver inflammation, and fibrotic features were monitored by performing an in vivo study. We have also performed a Next-Gene transcriptomic analysis of the transgenic mice liver tissue 16 h after lipopolysaccharide (LPS) administration to delineate liver inflammatory response in Pi*Z mice as compared with Pi*M. Our results show hepatic ZAAT accumulation, followed by hepatocyte ballooning and liver steatosis developed at 3 mo in Pi*Z mice compared with the mice carrying normal variant of human alpha-1 antitrypsin. We observed higher levels of hepatic immune cell infiltrations in both 3- and 6-mo-old Pi*Z mice compared with Pi*M as an indication of liver inflammation. Liver fibrosis was observed as accumulation of collagen in 6-mo-old Pi*Z liver tissues compared with Pi*M control mice. Furthermore, the transcriptomic analysis revealed a dysregulated liver immune response to LPS in Pi*Z mice compared with Pi*M. Of particular interest for translational work, this study aims to establish a mouse model of AATD with a strong manifestation of liver disease that will be a valuable in vivo tool to study the pathophysiology of AATD-mediated liver disease. Our data suggest that the human transgenic mouse model of AATD could provide a suitable model for the evaluation of therapeutic approaches and preventive reagents against AATD-mediated liver disease.NEW & NOTEWORTHY We have characterized a mouse model of human alpha-1 antitrypsin deficiency with a strong manifestation of liver disease that can be used as an in vivo tool to test preventive and therapeutic reagents. Our data explores the altered immunophenotype of alpha-1 antitrypsin-deficient liver macrophages and suggests a relationship between acute inflammation, immune response, and fibrosis.

Pharmacoepidemiological Research on N-Nitrosodimethylamine-Contaminated Ranitidine Use and Long-Term Cancer Risk: A Population-Based Longitudinal Cohort Study

N-Nitrosodimethylamine (NDMA), a carcinogenic chemical, has recently been identified in ranitidine. We conducted a population-based study to explore ranitidine use and cancer emergence over time. Using the Taiwan National Health Insurance Research Database, a population-based cohort study was conducted. A total of 55,110 eligible patients who received ranitidine between January 2000 and December 2018 were enrolled in the treated cohort. We conducted a 1:1 propensity-score-matching procedure to match the ranitidine-treated group with the ranitidine-untreated group and famotidine controls for a longitudinal study. The association of ranitidine exposure with cancer outcomes was assessed. A multivariable Cox regression analysis that compared cancer risk with the untreated groups revealed that ranitidine increased the risk of liver (hazard ratio (HR): 1.22, 95% confidence interval (CI): 1.09-1.36, p < 0.001), lung (HR: 1.17, CI: 1.05-1.31, p = 0.005), gastric (HR: 1.26, CI: 1.05-1.52, p = 0.012), and pancreatic cancers (HR 1.35, CI: 1.03-1.77, p = 0.030). Our real-world observational study strongly supports the pathogenic role of NDMA contamination, given that long-term ranitidine use is associated with a higher likelihood of liver cancer development in ranitidine users compared with the control groups of non-ranitidine users treated with famotidine or proton-pump inhibitors.

Chrysophanol-8-O-glucoside protects mice against acute liver injury by inhibiting autophagy in hepatic stellate cells and inflammatory response in liver-resident macrophages

Acute liver failure (ALF) is an unfavorable condition characterized by the rapid loss of liver function and high mortality. Chrysophanol-8-O-glucoside (CPOG) is an anthraquinone derivative isolated from rhubarb. This study aims to evaluate the protective effect of CPOG on lipopolysaccharide (LPS)/D-GalN-induced ALF and its underlying mechanisms. LPS/D-GalN-induced mice ALF model and LPS treatment model in RAW 264.7 and LX2 cells were established. It was found that CPOG ameliorated LPS/D-GalN-induced liver injury and improved mortality as indicated by Hematoxylin-eosin (H&amp;E) staining. Molecularly, qPCR and ELISA results showed that CPOG alleviated LPS/D-GalN-induced release of alanine aminotransferase and aspartate transaminase and the secretion of TNF-α and IL-1β in vivo. LPS/D-GalN-induced intracellular ROS production was also attenuated by CPOG in liver tissue. Further, CPOG attenuated ROS generation and inhibited the expression of p-IκB and p-p65 as well as the expression of TNF-α and IL-1β stimulated by LPS in RAW 264.7 cells. In addition, CPOG alleviated LPS-induced up-regulation of LC3B, p62, ATG5 and Beclin1 by attenuating ROS production and inhibiting MAPK signaling in LX2 cells. Taken together, our data indicated that the CPOG protected against LPS/D-GalN-induced ALF by inhibiting oxidative stress, inflammation response and autophagy. These findings suggest that CPOG could be potential drug for the treatment of ALF in clinic.

Inflammation aggravated the hepatotoxicity of triptolide by oxidative stress, lipid metabolism disorder, autophagy, and apoptosis in zebrafish

Triptolide is a major compound isolated from the Tripterygium wilfordii Hook that is mainly used for the treatment of autoimmune disorders and inflammatory diseases. Though triptolide-induced hepatotoxicity has been widely reported, the hepatic effects when the patients are in an inflammatory state are not clear. In this study, we used low-dose Lipopolysaccharides (LPS) to disrupt the inflammation homeostasis in the liver of zebrafish and explored the hepatotoxicity of triptolide under an inflammatory state. Compared with the Triptolide group, LPS-Triptolide cotreatment exacerbate the liver injury with a remarkable decrease of liver size and liver-specific fluorescence intensity, accompanied by significant elevation of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. Liver cell damages were further demonstrated by histological staining and scanning electron microscopy observation. Lipid metabolism was severely impaired as indicated by delayed yolk sac absorption, accumulated triglycerides in the liver, and dysregulation of the related genes, such as ppar-α, cpt-1, mgst, srebf1/2, and fasn. Oxidative stress could be involved in the molecular mechanism as the Nrf2/keap1 antioxidant pathways were down-regulated when the zebrafish in an inflammatory state. Moreover, the expression of autophagy-related genes such as beclin, atg5, map1lc3b, and atg3 was also dysregulated. Finally, apoptosis was significantly induced in responses to LPS-Triptolide co-treatment. We speculate that triptolide could exacerbate the immune response and impair lipid metabolism, resulting in enhanced sensitivity of the zebrafish liver to triptolide-induced toxic effects through disruption of the antioxidant system and induction of apoptosis.

Seminal and histopathological alterations in bucks challenged with Mannheimia haemolytica serotype a2 and its LPS endotoxin

Pneumonic mannheimiosis is a widespread respiratory bacterial disease of small ruminants caused by Mannheimia haemolytica serotype A2. The disease is known to affect the respiratory organs of infected animals, but its effect on other vital and reproductive organs has not been fully explored. Previous studies have demonstrated increased serum pro-inflammatory cytokine concentration post-challenge with M. haemolytica A2 and its LPS, indicating systemic inflammation in the host. This study determined the potential tissue changes and alterations of sperm parameters due to infection of M. haemolytica A2 and its LPS endotoxin. In this study, twelve experimental bucks were randomly assigned to three groups of four bucks each: group 1 (control group) were intranasally inoculated with 2 mL of PBS pH 7.0, group 2 received 2 mL of 1.2 × 10⁹ CFU/mL M. haemolytica A2 intranasally, and group 3 received 2 mL of LPS extracted from 1.2 × 10⁹ CFU/mL of M. haemolytica A2 intravenously. Semen samples were collected at pre-determined intervals using an electro-ejaculator and analysed immediately after collection. All experimental bucks were slaughtered via exsanguination on day 60 to collect their vital and reproductive organs at necropsy, and the samples were processed and analysed for histopathological changes. The current study has revealed that bucks challenged with M. haemolytica A2 and its LPS exhibited alterations in semen parameters such as motility, wave pattern, viability, and morphological abnormalities. Mild to moderate histopathological changes of the lung, liver, testis, epididymis, vas deferens, prostate, and lymph nodes were also observed in both challenged groups. Therefore, this study revealed the potential harmful effects of respiratory mannheimiosis on the reproductive organs of the infected bucks and sheds light on the expanse of systemic effects of this disease.

Distinct responses between healthy and cirrhotic human livers upon lipopolysaccharide challenge: possible implications for acute-on-chronic liver failure

Patients with acute-on-chronic liver failure (ACLF) are at risk of developing acute hepatic decompensation and organ failures with an unraveled complex mechanism. An altered immune response toward insults in cirrhotic compared with healthy livers may contribute to the ACLF development. Therefore, we aim to investigate the differences in inflammatory responses between cirrhotic and healthy livers using human precision-cut liver slices (PCLSs) upon the lipopolysaccharide (LPS) challenge. PCLSs prepared from livers of patients with cirrhosis or healthy donors of liver transplantation were incubated ex vivo with or without LPS for up to 48 h. Viability test, qRT-PCR, and multiplex cytokine assay were performed. Regulation of the LPS receptors during incubation or with LPS challenge differed between healthy versus cirrhotic PCLSs. LPS upregulated TLR-2 in healthy PCLSs solely (P < 0.01). Culturing for 48 h induced a stronger inflammatory response in the cirrhotic than healthy PCLS. Upon LPS stimulation, cirrhotic PCLSs secreted more proinflammatory cytokines (IL-8, IL-6, TNF-α, eotaxin, and VEGF) significantly and less anti-inflammatory cytokine (IL-1ra) than those of healthy. In summary, cirrhotic PCLSs released more proinflammatory and less anti-inflammatory cytokines after LPS stimuli than healthy, leading to dysregulated inflammatory response. These events could possibly resemble the liver immune response in ACLF.NEW & NOTEWORTHY Precision-cut liver slices (PCLSs) model provides a unique platform to investigate the different immune responses of healthy versus cirrhotic livers in humans. Our data show that cirrhotic PCLSs exhibit excessive inflammatory response accompanied by a lower anti-inflammatory cytokine release in response to LPS; a better understanding of this alteration may guide the novel therapeutic approaches to mitigate the excessive inflammation during the onset of acute-on-chronic liver failure.

Effects of probiotics combined with dietary and lifestyle modification on clinical, biochemical, and radiological parameters in obese children with nonalcoholic fatty liver disease/nonalcoholic steatohepatitis: a randomized clinical trial

BACKGROUND

Childhood obesity is a global problem associated with metabolic abnormalities. The gut-liver axis is thought to play a major role in its pathogenesis. Probiotics are known to alter the gut microbiota and, therefore, could be a therapeutic option in the management of childhood obesity-related complications.

PURPOSE

This double-blind randomized placebo-controlled trial evaluated the effects of probiotics on metabolic derangement in obese children with nonalcoholic fatty liver disease/ nonalcoholic steatohepatitis (NAFLD/NASH).

METHODS

Obese children with NAFLD/NASH treated at the nutrition clinic of the University Paediatric Unit at Lady Ridgeway Hospital, Colombo, were recruited. Anthropometry, body fat, metabolic derangement, and liver ultrasound scan (USS) results were evaluated at baseline and after 6 months. Transient elastography (FibroScan) was performed on a subsample of these patients. Eighty-four patients were recruited and randomized into the probiotics (n=43) and placebo (n= 41) groups. The mean age was 11.3±1.9 versus 12.1±1.5 years in the probiotic and placebo groups, respectively. Baseline parameters including liver disease stage on USS, body fat percentage, fasting blood sugar, lipid profile, liver function, and C-reactive protein showed no significant intergroup differences.

RESULTS

In the probiotic group, a statistically significant reduction in body mass index was noted from the baseline value. However, the reduction was not significant compared with the placebo group. There was a significant reduction in triglycerides, aspartate transaminase (AST), alanine aminotransferase (ALT), AST/ALT ratio, and alkaline phosphatase in the placebo group over the treatment period. Although the liver disease stage on USS improved from stage II-III to stage I in a small number of patients in the probiotic-treated group, transient elastography performed in a subsample did not demonstrate significant improvement in either group.

CONCLUSION

Our results indicate that probiotics have no advantage over lifestyle modification for improving obesityassociated metabolic derangement in children.

Systemic Effects of mitoTEMPO upon Lipopolysaccharide Challenge Are Due to Its Antioxidant Part, While Local Effects in the Lung Are Due to Triphenylphosphonium

Mitochondria-targeted antioxidants (mtAOX) are a promising treatment strategy against reactive oxygen species-induced damage. Reports about harmful effects of mtAOX lead to the question of whether these could be caused by the carrier molecule triphenylphosphonium (TPP). The aim of this study was to investigate the biological effects of the mtAOX mitoTEMPO, and TPP in a rat model of systemic inflammatory response. The inflammatory response was induced by lipopolysaccharide (LPS) injection. We show that mitoTEMPO reduced expression of inducible nitric oxide synthase in the liver, lowered blood levels of tissue damage markers such as liver damage markers (aspartate aminotransferase and alanine aminotransferase), kidney damage markers (urea and creatinine), and the general organ damage marker, lactate dehydrogenase. In contrast, TPP slightly, but not significantly, increased the LPS-induced effects. Surprisingly, both mitoTEMPO and TPP reduced the wet/dry ratio in the lung after 24 h. In the isolated lung, both substances enhanced the increase in pulmonary arterial pressure induced by LPS observed within 3 h after LPS treatments but did not affect edema formation at this time. Our data suggest that beneficial effects of mitoTEMPO in organs are due to its antioxidant moiety (TEMPO), except for the lung where its effects are mediated by TPP.

Integrated bioinformatics analyses of key genes involved in hepatocellular carcinoma immunosuppression

Hepatocellular carcinoma (HCC) is a typical inflammation-driven cancer. Chronically unresolved inflammation may remodel the immunosuppressive tumor microenvironment, which is rich in innate immune cells. The mechanisms via which HCC progresses through the evasion of the innate immune surveillance remain unclear. The present study thus aimed to identify key genes involved in HCC immunosuppression and to establish an innate immune risk signature, with the ultimate goal of obtaining new insight into effective immunotherapies. HCC and normal liver tissue mRNA expression and clinicopathological data were obtained from the Cancer Genome Atlas database. The immunosuppressive innate immune-related genes (IIRGs) in HCC were screened using integrated bioinformatics analyses. Gene expression was then validated using the Gene Expression Omnibus database and the Human Protein Atlas database, and tissues were obtained from patients with HCC who underwent surgery. In total, 3,676 genes were identified as differentially expressed mRNAs after comparing the HCC tissues with the normal liver tissues in TCGA. Gene Set Enrichment Analyses revealed 21 highly expressed IIRGs in HCC tissues. A survival analysis and Cox regression model were used to construct an innate immune risk signature, including three IIRGs: Collectin-12 (COLEC12), matrix metalloproteinase-12 (MMP12) and mucin-12 (MUC12) genes. Univariate and multivariate Cox analyses revealed that the signature of the three IIRGs was a robust independent risk factor in relation to the overall survival (OS) of patients with HCC. The expression of the three aforementioned IIRGs was confirmed through external validation. Moreover, COLEC12 and MMP12 expression significantly correlated with that of immune checkpoint molecules or immunosuppressive cytokines. The tumor immune dysfunction and exclusion tool predicted that the increased expression of the three IIRGs in patients with HCC was significantly associated with the efficacy of relatively poor immune checkpoint blockade therapy. Conclusively, a novel innate immune-related risk signature for patients with HCC was constructed and validated. This signature may be involved in immunosuppression, and may be used to predict a poor prognosis, functioning as a potential immunotherapeutic target for patients with HCC.

Deletion of TLR4 attenuates lipopolysaccharide-induced acute liver injury by inhibiting inflammation and apoptosis

Septic acute liver injury is one of the leading causes of fatalities in patients with sepsis. Toll-like receptor 4 (TLR4) plays a vital role in response to lipopolysaccharide (LPS) challenge, but the mechanisms underlying TLR4 function in septic injury remains unclear. In this study, we investigated the role of TLR4 in LPS-induced acute liver injury (ALI) in mice with a focus on inflammation and apoptosis. Wild-type (WT) and TLR4-knockout (TLR4-/-) mice were challenged with LPS (4 mg/kg) for 6 h. TLR4 signaling cascade markers (TLR4, MyD88, and NF-κB), inflammatory markers (TNFα, IL-1β, and IL-6), and apoptotic markers (Bax, Bcl-2, and caspase 3) were evaluated. We showed that LPS challenge markedly increased the levels of serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST) and other liver pathological changes in WT mice. In addition, LPS challenge elevated the levels of liver carbonyl proteins and serum inflammatory cytokines, upregulated the expression of TLR4, MyD88, and phosphorylated NF-κB in liver tissues. Moreover, LPS challenge significantly increased hepatocyte apoptosis, caspase 3 activity, and Bax level while suppressing Bcl-2 expression in liver tissues. These pathological changes were greatly attenuated in TLR4-/- mice. Similar pathological responses were provoked in primary hepatic Kupffer cells isolated from WT and TLR4-/- mice following LPS (1 μg/mL, 6 h) challenge. In summary, these results demonstrate that silencing of TLR4 attenuates LPS-induced liver injury through inhibition of inflammation and apoptosis via TLR4/MyD88/NF-κB signaling pathway. TLR4 deletion confers hepatoprotection against ALI induced by LPS, possibly by repressing macrophage inflammation and apoptosis.

Effect of Endotoxemia Induced by Intraperitoneal Injection of Lipopolysaccharide on the Mg isotopic Composition of Biofluids and Tissues in Mice

Endotoxemia induced in vivo in mice by intraperitoneal injection of lipopolysaccharide (LPS) leads to (neuro)inflammation and sepsis. Also the homeostasis of mineral elements can be altered through mechanisms that still are poorly understood. The isotopic composition of Mg and the concentrations of the minor elements Ca, K, Mg, Na, P, and S were determined in biological fluids and tissues of young (14–28 weeks) and aged (40–65 weeks) LPS-injected mice and age-matched controls to reveal potential effects of the LPS-induced infection. Blood plasma of young and aged LPS-injected mice showed a heavy Mg isotopic composition, as well as elevated Mg and P concentrations, compared to matched controls. The plasma Mg isotopic composition was correlated with the P concentration in aged mice. Also the liver Mg isotopic composition was strongly affected in the young and aged LPS-injected mice, while for aged mice, an additional effect on the urine Mg isotopic composition was established. These observations were hypothetically associated with liver inflammation and/or hepatotoxicity, and reduced urinary Mg excretion, respectively. Also a regional endotoxin-induced difference was observed in the brain Mg isotopic composition for the aged mice only, and was attributed to potential disruption of the blood-brain barrier.

Expression of the Metalloproteinase ADAM8 Is Upregulated in Liver Inflammation Models and Enhances Cytokine Release In Vitro

Acute and chronic liver inflammation is driven by cytokine and chemokine release from various cell types in the liver. Here, we report that the induction of inflammatory mediators is associated with a yet undescribed upregulation of the metalloproteinase ADAM8 in different murine hepatitis models. We further show the importance of ADAM8 expression for the production of inflammatory mediators in cultured liver cells. As a model of acute inflammation, we investigated liver tissue from lipopolysaccharide- (LPS-) treated mice in which ADAM8 expression was markedly upregulated compared to control mice. In vitro, stimulation with LPS enhanced ADAM8 expression in murine and human endothelial and hepatoma cell lines as well as in primary murine hepatocytes. The enhanced ADAM8 expression was associated with an upregulation of TNF-α and IL-6 expression and release. Inhibition studies indicate that the cytokine response of hepatoma cells to LPS depends on the activity of ADAM8 and that signalling by TNF-α can contribute to these ADAM8-dependent effects. The role of ADAM8 was further confirmed with primary hepatocytes from ADAM8 knockout mice in which TNF-α and IL-6 induction and release were considerably attenuated. As a model of chronic liver injury, we studied liver tissue from mice undergoing high-fat diet-induced steatohepatitis and again observed upregulation of ADAM8 mRNA expression compared to healthy controls. In vitro, ADAM8 expression was upregulated in hepatoma, endothelial, and stellate cell lines by various mediators of steatohepatitis including fatty acid (linoleic-oleic acid), IL-1β, TNF-α, IFN-γ, and TGF-β. Upregulation of ADAM8 was associated with the induction and release of proinflammatory cytokines (TNF-α and IL-6) and chemokines (CX3CL1). Finally, knockdown of ADAM8 expression in all tested cell types attenuated the release of these mediators. Thus, ADAM8 is upregulated in acute and chronic liver inflammation and is able to promote inflammation by enhancing expression and release of inflammatory mediators.

Co-administration of lipopolysaccharide and D-galactosamine induces genotoxicity in mouse liver

The acute liver injury (ALI) and hepatic fibrosis caused by the co-treatment of lipopolysaccharide (LPS)/d-galactosamine (D-GalN) have been extensively studied. However, whether LPS/D-GalN are genotoxic has been left unknown. In this study, male mice were divided into eight groups with eight animals in each group. For acute challenge of LPS/D-GalN, the mice in each group received a combination of LPS/D-GalN via intraperitoneal injection at the dose of 25 μg/kg/250 mg/kg, 25 μg/kg/500 mg/kg, or 50 μg/kg/500 mg/kg body weight. An additional group for chronic administration of test compounds was conducted by i.p. injection of LPS/D-GalN (10 μg/kg/100 mg/kg) every other day for 8 weeks. Saline solution (0.9%) and cyclophosphamide (CTX) (50 mg/kg body weight) given by i.p. injection was used as the negative and positive control, respectively. The results of single cell gel electrophoresis (SCGE) assay indicated that acute exposure of the mice to LPS/D-GalN caused severe DNA damage in hepatic cells, but not in the brain, sperm or bone marrow cells, which evidenced the genotoxicity of LPS/D-GalN administrated in combination. Interestingly, the chronic administration of LPS/D-GalN triggered significant genotoxic effects not only in hepatic but also in brain cells, with negative results in sperm and bone marrow cells. Histopathological examination in the liver and brain tissues revealed changes consistent with the SCGE results. The present study indicates genotoxic potential of LPS/D-GalN co-administered in mice, which may serve as an in vivo experimental model for relevant genotoxic study.

Time-of-Day-Dependent Gating of the Liver-Spinal Axis Initiates an Anti-Inflammatory Reflex in the Rat

The autonomic nervous system (ANS) modulates the immune response through the engagement of an anti-inflammatory reflex. There is controversy regarding which efferent branch of the ANS, sympathetic or parasympathetic, downregulates the intensity of the inflammatory response. Furthermore, how information about the immune status of the body reaches the CNS to engage this reflex remains unclear. The present study demonstrates the existence of a liver-spinal axis that conveys early circulating inflammatory information to the CNS in response to lipopolysaccharide (LPS) and serves as the afferent arm of a sympathetic anti-inflammatory reflex. Furthermore, brainstem and spinal cord visceral sensory neurons show a time-of-day-dependent sensitivity to the incoming inflammatory information, in particular, prostaglandins (PG). Consequentially, the liver-spinal axis promotes the retention of tumor necrosis factor α (TNFα) in the liver and spleen during the resting period, resulting in low plasmatic TNFα levels. Consistently, low sensitivity for LPS during the active period promotes the release of TNFα from the organs into the circulation, resulting in high plasmatic TNFα levels. The present novel findings illustrate how the time-of-day-dependent activation of the liver-spinal axis contributes to the daily fluctuations of the inflammatory response.

Hepatic Inflammatory Response to Exogenous LPS Challenge is Exacerbated in Broilers with Fatty Liver Disease

This study aimed to examine hepatic function and inflammatory response in broilers with fatty livers, following acute lipopolysaccharide (LPS) challenge. One-day-old Lihua yellow broilers were fed a basal diet. Broilers were divided into four groups: control (CON), corticosterone treatment (CORT), LPS treatment (LPS), and LPS and CORT treatment (LPS&CORT). Results show that CORT induced an increase in plasma and liver triglycerides (TGs), which were accompanied by severe hepatic steatosis. The LPS group showed hepatocyte necrosis with inflammatory cell infiltration. Total liver damage score in the LPS&CORT group was significantly higher than that in the LPS group (p < 0.05). Activity levels of plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were similar in the CON and CORT groups, but higher in the LPS group. Gene expression upregulation of the proinflammatory cytokines (NF-κB, IL-1β, IL-6, IFN-γ, and iNOS) was also noted in the LPS group (p < 0.05). In particular, LPS injection exacerbated the gene expression of these proinflammatory cytokines, even when accompanied by CORT injections (p < 0.05). In summary, our results indicate that broilers suffering from fatty liver disease are more susceptible to the negative effects of LPS, showing inflammatory response activation and more severe damages to the liver.

Reduced Neutrophil Extracellular Trap (NET) Formation During Systemic Inflammation in Mice With Menkes Disease and Wilson Disease: Copper Requirement for NET Release

Neutrophil extracellular traps (NETs) contribute to pathological disorders, and their release was directly linked to numerous diseases. With intravital microscopy (IVM), we showed previously that NETs also contribute to the pathology of systemic inflammation and are strongly deposited in liver sinusoids. Over a decade since NET discovery, still not much is known about the metabolic or microenvironmental aspects of their formation. Copper is a vital trace element essential for many biological processes, albeit its excess is potentially cytotoxic; thus, copper levels are tightly controlled by factors such as copper transporting ATPases, ATP7A, and ATP7B. By employing IVM, we studied the impact of copper on NET formation during endotoxemia in liver vasculature on two mice models of copper excess or deficiency, Wilson (ATP7B mutants) and Menkes (ATP7A mutants) diseases, respectively. Here, we show that respective ATP7 mutations lead to diminished NET release during systemic inflammation despite unaltered intrinsic capacity of neutrophils to cast NETs as tested ex vivo. In Menkes disease mice, the in vivo effect is mostly due to diminished neutrophil infiltration of the liver as unmutated mice with a subchronic copper deficiency release even more NETs than their controls during endotoxemia, whereas in Wilson disease mice, excess copper directly diminishes the capacity to release NETs, and this was further confirmed by ex vivo studies on isolated neutrophils co-cultured with exogenous copper and a copper-chelating agent. Taken together, the study extends our understanding on how microenvironmental factors affect NET release by showing that copper is not a prerequisite for NET release but its excess affects the trap casting by neutrophils.

Potent repression of C-reactive protein (CRP) expression by the JAK1/2 inhibitor ruxolitinib in inflammatory human hepatocytes

OBJECTIVE AND DESIGN

To determine whether inflammatory hepatocytes may constitute primary targets for ruxolitinib, a Janus kinase (JAK) inhibitor, its effects towards expression of hepatic acute-phase proteins, especially C-reactive protein (CRP), were assessed.

MATERIALS

Ruxolitinib effects were analysed in primary human hepatocytes and human hepatoma HepaRG cells exposed to various inflammatory stimuli.

RESULTS

Ruxolitinib was found to fully inhibit lipopolysaccharide (LPS)-induced CRP secretion and mRNA expression, at concentrations (IC₅₀ = 12.9 nM) achievable in human blood. It similarly repressed CRP up-regulation due to several Toll-like receptor agonists or pro-inflammatory cytokines [interleukin (IL) 1β, IL6 and tumour necrosis factor α] and counteracted LPS-mediated induction of serum amyloid A, fibrinogen, haptoglobin and serpin. Ruxolitinib was additionally found to block the activation of the IL6/JAK/signal transducer and activator of transcription (STAT) pathway triggered by LPS and whose inhibition by the neutralizing anti-IL6 receptor antibody tocilizumab prevented CRP induction.

CONCLUSION

Ruxolitinib can potently repress induction of CRP in inflammatory human hepatocytes, most likely through targeting the IL6/JAK/STAT signalling cascade. Hepatic production of acute-phase proteins during liver inflammation may, therefore, constitute a target for ruxolitinib.

Role of endotoxemia in causing renal dysfunction in cirrhosis

Renal failure is a challenging problem in patients with cirrhosis since mortality increases with worsening renal function, hence the inclusion of serum creatinine in calculating the Model for End-Stage Liver Disease score for liver transplant evaluation. Among the various causes, infection is the leading etiology of mortality associated with cirrhosis. Bacterial infection frequently precipitates renal failure in patients with cirrhosis with the reported prevalence around 34%. Patients with cirrhosis are at increased risk of infections due to impaired immunity and increased gut permeability leading to bacterial translocation in the setting of portal hypertension. One of the most feared complications of severely decompensated liver and renal failure is hepatorenal syndrome, of which liver transplant may be the only available treatment. Furthermore, in those with spontaneous bacterial peritonitis and urinary tract infection, progressive renal failure occurs despite resolution of infection. Thus, the effects of endotoxemia on renal function in cirrhosis have become a major focus of research. The mechanisms of the damaging effects of endotoxin on renal function are complex but, in essence, involve dysregulated inflammation, circulatory dysfunction, poor clearance of endotoxin burden, as well as vasomotor nephropathy. In this article, we will review the mechanisms of endotoxemia-induced renal dysfunction in the setting of cirrhosis through the effects on renal blood flow, renal vascular endothelium, glomerular filtration rate, and tubular function.

Altered Intestinal Morphology and Microbiota Composition in the Autism Spectrum Disorders Associated SHANK3 Mouse Model

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders characterized by deficits in social interaction and communication, and repetitive behaviors. In addition, co-morbidities such as gastro-intestinal problems have frequently been reported. Mutations and deletion of proteins of the SH3 and multiple ankyrin repeat domains (SHANK) gene-family were identified in patients with ASD, and Shank knock-out mouse models display autism-like phenotypes. SHANK3 proteins are not only expressed in the central nervous system (CNS). Here, we show expression in gastrointestinal (GI) epithelium and report a significantly different GI morphology in Shank3 knock-out (KO) mice. Further, we detected a significantly altered microbiota composition measured in feces of Shank3 KO mice that may contribute to inflammatory responses affecting brain development. In line with this, we found higher E. coli lipopolysaccharide levels in liver samples of Shank3 KO mice, and detected an increase in Interleukin-6 and activated astrocytes in Shank3 KO mice. We conclude that apart from its well-known role in the CNS, SHANK3 plays a specific role in the GI tract that may contribute to the ASD phenotype by extracerebral mechanisms.

Impact of Nutritional Changes on Nonalcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a major global health threat due to its growing incidence and prevalence. It is becoming the leading cause of liver disease in addition to its strong association with cardio-metabolic disease. Therefore, its prevention and treatment are of strong public interest. Therapeutic approaches emphasize lifestyle modifications including physical activity and the adoption of healthy eating habits that intend to mainly control body weight and cardio-metabolic risk factors associated with the metabolic syndrome. Lifestyle interventions may be reinforced by pharmacological treatment in advanced stages, though there is still no registered drug for the specific treatment of NAFLD. The purpose of this review is to assess the evidence available regarding the impact of dietary recommendations against NAFLD, highlighting the effect of macronutrient diet composition and dietary patterns in the management of NAFLD.

Effect of Moxibustion on Intestinal Microbiome in Acute Gastric Ulcer Rats

In Traditional Chinese Medicine (TCM), moxibustion had been used for thousands of years. Many clinical case reports and scientific studies had proved that moxibustion had a good effect in treating acute gastric ulcer (AGU). Some studies had shown that the relative content and species of bacteria in the intestinal would be changed when gastric mucosal injury happened. However, there was little research on the effect of intestinal microbiome with AGU rats that were treating by moxibustion. This study is aimed at analyzing the effect of fecal microbiome in rats with AGU by the 16S rDNA sequencing technology. Male SD rats were established by orally feeding once with 70% ethanol at 4 ml/kg except the control group, then treated by moxibustion in the stomach meridian group ("Liangmen," "Zusanli") and the gallbladder meridian group ("Riyue," "Yanglingquan") for 5 days. The 16S rDNA sequencing technology analysis of feces combined with histopathological methods and molecular biological detection methods was used to evaluate the therapeutic mechanism of moxibustion on AGU. AGU brought cause changes in the number and species of intestinal bacteria. Moxibustion on stomach meridian group could reduce the area of gastric mucosal injury and regulate the relative content of GAS and EGF. Moreover, moxibustion on the stomach meridian group could increase the relative content and species of beneficial bacteria in the intestine of rats with AGU. The relative abundance of intestinal probiotics was significantly upregulated in Alphaproteobacteria, Actinomycetales, and Bacillales. In addition, moxibustion might promote the repair of gastric mucosal injury by increasing the number and species of beneficial bacteria in the intestine.

Deletion of caveolin-1 attenuates LPS/GalN-induced acute liver injury in mice

Acute hepatic injury caused by inflammatory liver disease is associated with high mortality. This study examined the role of caveolin-1 (Cav-1) in lipopolysaccharide (LPS) and D-galactosamine (GalN)-induced fulminant hepatic injury in wild type and Cav-1-null (Cav-1-/- ) mice. Hepatic Cav-1 expression was induced post-LPS/GalN treatment in wild-type mice. LPS/GalN-treated Cav-1-/- mice showed reduced lethality and markedly attenuated liver damage, neutrophil infiltration and hepatocyte apoptosis as compared to wild-type mice. Cav-1 deletion significantly reduced LPS/GalN-induced caspase-3, caspase-8 and caspase-9 activation and pro-inflammatory cytokine and chemokine expression. Additionally, Cav-1-/- mice showed suppressed expression of Toll-like receptor 4 (TLR4) and CD14 in Kupffer cells and reduced expression of vascular cell adhesion molecule 1 and intercellular adhesion molecule 1 in liver cells. Cav-1 deletion impeded LPS/GalN-induced inducible nitric oxide synthase expression and nitric oxide production and hindered nuclear factor-κB (NF-κB) activation. Taken together, Cav-1 regulated the expression of mediators that govern LPS-induced inflammatory signalling in mouse liver. Thus, deletion of Cav-1 suppressed the inflammatory response mediated by the LPS-CD14-TLR4-NF-κb pathway and alleviated acute liver injury in mice.

Modulation of gut microbiome in nonalcoholic fatty liver disease: pro-, pre-, syn-, and antibiotics

Nonalcoholic fatty liver disease (NAFLD) is one of the most common types of liver diseases worldwide and its incidence continues to increase. NAFLD occurs when the body can no longer effectively store excess energy in the adipose tissue. Despite the increasing prevalence of NAFLD, making lifestyle changes, including increased exercise, is often an elusive goal for patients with NAFLD. The liver directly connects to the gut-gastrointestinal milieu via the portal vein, which are all part of the gut-liver axis. Therefore, the gut-microbiome and microbial products have been actively studied as likely key factors in NAFLD pathophysiology. Hence, dysbiosis of the gut microbiome and therapeutic manipulation of the gut-liver axis are being investigated. Novel therapeutic approaches for modulating gut microbiota through the administration of probiotics, prebiotics, synbiotics, and antibiotics have been proposed with numerous promising initial reports on the effectiveness and clinical applications of these approaches. This review delves into the current evidence on novel therapies that modulate gut microbiota and discusses ongoing clinical trials targeting the gut-liver axis for the management and prevention of NAFLD.

The Acute-on-Chronic Liver Failure Syndrome, or When the Innate Immune System Goes Astray

The acute-on-chronic liver failure (ACLF) syndrome is characterized by acute decompensation of cirrhosis, organ failure, and high 28-d mortality. ACLF displays key features of systemic inflammation and its poor outcome is closely associated with exacerbated systemic inflammatory responses. In this review, we describe the prevailing characteristics of systemic inflammation in patients with decompensated cirrhosis and ACLF, with special emphasis on the principal features of the cytokine storm the mechanisms underlying this intense systemic inflammatory response (i.e., presence of circulating pathogen- and damage-associated molecular patterns), and their implication in tissue and organ damage in this condition.

Dietary Composition Independent of Weight Loss in the Management of Non-Alcoholic Fatty Liver Disease

Poor dietary composition is an important factor in the progression of non-alcoholic fatty liver disease (NAFLD). The majority of NAFLD patients follow diets with overconsumption of simple carbohydrates, total and saturated fat, with reduced intake of dietary fiber and omega-3 rich foods. Although lifestyle modifications including weight loss and exercise remain the keystone of NAFLD management, modifying dietary composition with or without a calorie-restricted diet may also be a feasible and sustainable strategy for NAFLD treatment. In the present review article, we highlight the potential therapeutic role of a “high quality healthy diet” to improve hepatic steatosis and metabolic dysfunction in patients with NAFLD, independent of caloric restriction and weight loss. We provide a literature review evaluating the evidence behind dietary components including fiber-, meat- and omega-3-rich diets and, pending further evidence, we concur with the EASL-EASD-EASO Clinical Guidelines recommendation of the Mediterranean diet as the diet of choice in these patients.

JNK signaling is required for the MIP‑1α‑associated regulation of Kupffer cells in the heat stroke response

Severe heat stroke (HS) consists of extreme hyperthermia with thermoregulatory failure, leading to high morbidity and mortality. Liver injury is a complication of HS that is associated with inflammatory responses and Kupffer cells (KCs), which are resident macrophages in the liver that serve as a major source of inflammatory cytokines; however, the association and the underlying mechanisms of KC functions in HS-induced endotoxemia and inflammation require an improved understanding. The important chemokine macrophage inflammatory protein-1α (MIP-1α) increases inflammatory responses and the secretion of inflammatory molecules from KCs, including tumor necrosis factor-α, interleukin (IL)-1β and IL-6. In addition, the activation of c-Jun N-terminal kinase (JNK) signaling is responsible for the development of liver inflammation. Therefore, HS animal and cell models were constructed in order to investigate the pathways involved in the HS-induced dysfunction of KCs. The results of the present study suggest that JNK may be involved in the MIP-1α-associated pathogenesis of KCs in HS injury.

Mast cells mediate early neutrophil recruitment and exhibit anti-inflammatory properties via the formyl peptide receptor 2/lipoxin A4 receptor

BACKGROUND AND PURPOSE

In recent years, studies have focused on the resolution of inflammation, which can be achieved by endogenous anti-inflammatory agonists such as Annexin A1 (AnxA1). Here, we investigated the effects of mast cells (MCs) on early LPS-induced neutrophil recruitment and the involvement of the AnxA1-formyl peptide receptor 2/ALX (FPR2/ALX or lipoxin A₄ receptor) pathway.

EXPERIMENTAL APPROACH

Intravital microscopy (IVM) was used to visualize and quantify the effects of LPS (10 μg per mouse i.p.) on murine mesenteric cellular interactions. Furthermore, the role that MCs play in these inflammatory responses was determined in vivo and in vitro, and effects of AnxA1 mimetic peptide Ac2-26 were assessed.

KEY RESULTS

LPS increased both neutrophil endothelial cell interactions within the mesenteric microcirculation and MC activation (determined by IVM and ruthenium red dye uptake), which in turn lead to the early stages of neutrophil recruitment. MC recruitment of neutrophils could be blocked by preventing the pro-inflammatory activation (using cromolyn sodium) or enhancing an anti-inflammatory phenotype (using Ac2-26) in MCs. Furthermore, MCs induced neutrophil migration in vitro, and MC stabilization enhanced the release of AnxA1 from neutrophils. Pharmacological approaches (such as the administration of FPR pan-antagonist Boc2, or the FPR2/ALX antagonist WRW4) revealed neutrophil FPR2/ALX to be important in this process.

CONCLUSIONS AND IMPLICATIONS

Data presented here provide evidence for a role of MCs, which are ideally positioned in close proximity to the vasculature, to act as sentinel cells in neutrophil extravasation and resolution of inflammation via the AnxA1-FPR2/ALX pathway.

Exposure to bacterial products lipopolysaccharide and flagellin and hepatocellular carcinoma: a nested case-control study

BACKGROUND

Leakage of bacterial products across the gut barrier may play a role in liver diseases which often precede the development of liver cancer. However, human studies, particularly from prospective settings, are lacking.

METHODS

We used a case-control study design nested within a large prospective cohort to assess the association between circulating levels of anti-lipopolysaccharide (LPS) and anti-flagellin immunoglobulin A (IgA) and G (IgG) (reflecting long-term exposures to LPS and flagellin, respectively) and risk of hepatocellular carcinoma. A total of 139 men and women diagnosed with hepatocellular carcinoma between 1992 and 2010 were matched to 139 control subjects. Multivariable rate ratios (RRs), including adjustment for potential confounders, hepatitis B/C positivity, and degree of liver dysfunction, were calculated with conditional logistic regression.

RESULTS

Antibody response to LPS and flagellin was associated with a statistically significant increase in the risk of hepatocellular carcinoma (highest vs. lowest quartile: RR = 11.76, 95% confidence interval = 1.70-81.40; P trend = 0.021). This finding did not vary substantially by time from enrollment to diagnosis, and did not change after adjustment for chronic infection with hepatitis B and C viruses.

CONCLUSIONS

These novel findings, based on exposures up to several years prior to diagnosis, support a role for gut-derived bacterial products in hepatocellular carcinoma development. Further study into the role of gut barrier failure and exposure to bacterial products in liver diseases is warranted.

Exosomes derived from human menstrual blood-derived stem cells alleviate fulminant hepatic failure

Background

Human menstrual blood-derived stem cells (MenSCs) are a novel source of MSCs that provide the advantage of being easy to collect and isolate. Exosomes contain some mRNAs and adhesion molecules that can potentially impact cellular and animal physiology. This study aimed to investigate the therapeutic potential of MenSC-derived exosomes (MenSC-Ex) on AML12 cells (in vitro) and D-GalN/LPS-induced FHF mice (in vivo).

Methods

Transmission electron microscopy and Western blot were used to identify MenSC-Ex. Antibody array was used to examine cytokine levels on MenSC-Ex. MenSC-Ex were treated in D-GalN/LPS-induced AML12 in vitro. Cell proliferation and apoptosis were measured. MenSC-Ex were injected into the tail veins of mice 24 h before treatment with D-GalN/LPS. Blood and liver tissues served as physiological and biochemical indexes. The number of liver mononuclear cells (MNCs) and the amount of the active apoptotic protein caspase-3 were determined to elaborate the mechanism of hepatoprotective activity.

Results

Human menstrual blood-derived stem cell-derived exosomes (MenSC-Ex) are bi-lipid membrane vesicles that have a round, ball-like shape with a diameter of approximately 30–100 nm. Cytokine arrays have shown that MenSC-Ex expressed cytokines, including ICAM-1, angiopoietin-2, Axl, angiogenin, IGFBP-6, osteoprotegerin, IL-6, and IL-8. MenSC-Ex markedly improved liver function, enhanced survival rates, and inhibited liver cell apoptosis at 6 h after transplantation. MenSC-Ex migrated to sites of injury and to AML12 cells (a mouse hepatocyte cell line), respectively. Moreover, MenSC-Ex reduced the number of liver mononuclear cells (MNCs) and the amount of the active apoptotic protein caspase-3 in injured livers.

Conclusions

In conclusion, our results provide preliminary evidence for the anti-apoptotic capacity of MenSC-Ex in FHF and suggest that MenSC-Ex may be an alternative therapeutic approach to treat FHF.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-016-0453-6) contains supplementary material, which is available to authorized users.

High Serum Lipopolysaccharide-Binding Protein Level in Chronic Hepatitis C Viral Infection Is Reduced by Anti-Viral Treatments

Background

Lipopolysaccharide-binding protein (LBP) has been reported to associate with metabolic diseases, such as obesity, diabetes, and non-alcoholic fatty liver disease. Since chronic hepatitis C virus (HCV) infection is associated with metabolic derangements, the relationship between LBP and HCV deserves additional studies. This study aimed to determine the serum LBP level in subjects with or without HCV infection and investigate the change of its level after anti-viral treatments with or without interferon.

Methods and Findings

We recruited 120 non-HCV subjects, 42 and 17 HCV-infected subjects respectively treated with peginterferon α-2a/ribavirin and direct-acting antiviral drugs. Basic information, clinical data, serum LBP level and abdominal ultrasonography were collected. All the subjects provided written informed consent before being enrolled approved by the Research Ethics Committee of the National Taiwan University Hospital. Serum LBP level was significantly higher in HCV-infected subjects than non-HCV subjects (31.0 ± 8.8 versus 20.0 ± 6.4 μg/mL; p-value < 0.001). After multivariate analyses, LBP at baseline was independently associated with body mass index, hemoglobin A1c, alanine aminotransferase (ALT) and HCV infection. Moreover, the baseline LBP was only significantly positively associated with ALT and inversely with fatty liver in HCV-infected subjects. The LBP level significantly decreased at sustained virologic response (27.4 ± 6.6 versus 34.6 ± 7.3 μg/mL, p-value < 0.001; 15.9 ± 4.4 versus 22.2 ± 5.7 μg/mL, p-value = 0.001), regardless of interferon-based or -free therapy.

Conclusions

LBP, an endotoxemia associated protein might be used as an inflammatory biomarker of both infectious and non-infectious origins in HCV-infected subjects.

Prebiotics: A Novel Approach to Treat Hepatocellular Carcinoma

Hepatocellular carcinoma is one of the fatal malignancies and is considered as the third leading cause of death. Mutations, genetic modifications, dietary aflatoxins, or impairments in the regulation of oncogenic pathways may bring about liver cancer. An effective barrier against hepatotoxins is offered by gut-liver axis as a change in gut permeability and expanded translocation of lipopolysaccharides triggers the activation of Toll-like receptors which stimulate the process of hepatocarcinogenesis. Prebiotics, nondigestible oligosaccharides, have a pivotal role to play when it comes to inducing an antitumor effect. A healthy gut flora balance is imperative to downregulation of inflammatory cytokines and reducing lipopolysaccharides induced endotoxemia, thus inducing the antitumor effect.

Ginseng for Liver Injury: Friend or Foe?

Panax sp., including Panax ginseng Meyer, Panax quiquifolius L., or Panax notoginseng (Burk.) FH Chen, have been used as functional foods or for traditional Chinese medicine for diabetes, inflammation, stress, aging, hepatic injury, and cancer. In recent decades, a number of both in vitro and in vivo experiments as well as human studies have been conducted to investigate the efficacy and safety of various types of ginseng samples and their components. Of these, the hepatoprotective and hepatotoxic effects of ginseng and their ginsenosides and polysaccharides are reviewed and summarized.

Pretreatment with lipopolysaccharide attenuates diethylnitrosamine-caused liver injury in mice via TLR4-dependent induction of Kupffer cell M2 polarization

In this study, we found that pretreatment with low dose of lipopolysaccharide (LPS), also known as lipoglycans and endotoxin, obviously attenuated liver injury caused by diethylnitrosamine (DEN) in mice. This protective effect was described by decreased ALT, TNF-α, and IL-1β and increased TGF-β production. However, Toll-like receptor 4-deficient (TLR4(-/-)) or macrophages depletion abolished this protection in mice, which revealed Kupffer cells (KCs) and TLR4 to be crucial for the prevention of LPS against DEN-induced damage. Further study revealed that LPS pretreatment induced the KCs to M2 polarization and impaired the signaling of MAPKs and NF-κB that mediated the production of inflammatory cytokines. Moreover, T regulatory cells (Tregs) were also recruited to the liver, which may mediate immunosuppression and participate in the prevention of DEN-induced injury. Our results suggested that LPS protected against DEN-induced hepatitis via induction of M2 Kupffer cells and recruitment of Tregs, which contributes to liver tolerance in TLR4-dependent mechanism.

Metabolic and hematological consequences of dietary deoxynivalenol interacting with systemic Escherichia coli lipopolysaccharide

Previous studies have shown that chronic oral deoxynivalenol (DON) exposure modulated Escherichia coli lipopolysaccharide (LPS)-induced systemic inflammation, whereby the liver was suspected to play an important role. Thus, a total of 41 barrows was fed one of two maize-based diets, either a DON-diet (4.59 mg DON/kg feed, n = 19) or a control diet (CON, n = 22). Pigs were equipped with indwelling catheters for pre- or post-hepatic (portal vs. jugular catheter) infusion of either control (0.9% NaCl) or LPS (7.5 µg/kg BW) for 1h and frequent blood sampling. This design yielded six groups: CON_CONjugular‑CONportal, CON_CONjugular‑LPSportal, CON_LPSjugular‑CONportal, DON_CONjugular‑CONportal, DON_CONjugular‑LPSportal and DON_LPSjugular‑CONportal. Blood samples were analyzed for blood gases, electrolytes, glucose, pH, lactate and red hemogram. The red hemogram and electrolytes were not affected by DON and LPS. DON-feeding solely decreased portal glucose uptake (p < 0.05). LPS-decreased partial oxygen pressure (pO₂) overall (p < 0.05), but reduced pCO₂ only in arterial blood, and DON had no effect on either. Irrespective of catheter localization, LPS decreased pH and base-excess (p < 0.01), but increased lactate and anion-gap (p < 0.01), indicating an emerging lactic acidosis. Lactic acidosis was more pronounced in the group DON_LPSjugular-CONportal than in CON-fed counterparts (p < 0.05). DON-feeding aggravated the porcine acid-base balance in response to a subsequent immunostimulus dependent on its exposure site (pre- or post-hepatic).

miR-150 Deficiency Protects against FAS-Induced Acute Liver Injury in Mice through Regulation of AKT

Although miR-150 is implicated in the regulation of immune cell differentiation and activation, it remains unknown whether miR-150 is involved in liver biology and disease. This study was performed to explore the potential role of miR-150 in LPS/D-GalN and Fas-induced liver injuries by using wild type and miR-150 knockout (KO) mice. Whereas knockout of miR-150 did not significantly alter LPS/D-GalN-induced animal death and liver injury, it protected against Fas-induced liver injury and mortality. The Jo2-induced increase in serum transaminases, apoptotic hepatocytes, PARP cleavage, as well as caspase-3/7, caspase-8, and caspase-9 activities were significantly attenuated in miR-150 KO mice. The liver tissues from Jo2-treated miR-150 KO mice expressed higher levels of Akt1, Akt2, total Akt, as well as p-Akt(Ser473) compared to the wild type livers. Pretreatment with the Akt inhibitor V reversed Jo2-induced liver injury in miR-150 KO mice. The primary hepatocytes isolated from miR-150 KO mice also showed protection against Fas-induced apoptosis in vitro (characterized by less prominent PARP cleavage, less nuclear fragmentation and less caspase activation) in comparison to hepatocytes from wild type mice. Luciferase reporter assays in hepatocytes transfected with the Akt1 or Akt2 3’-UTR reporter constructs (with or without mutation of miR-150 binding site) established Akt1 and Akt2 as direct targets of miR-150. Tail vein injection of lentiviral particles containing pre-miR-150 enhanced Jo2-induced liver injury in miR-150 KO mice. These findings demonstrate that miR-150 deficiency prevents Fas-induced hepatocyte apoptosis and liver injury through regulation of the Akt pathway.

The protection mechanism of proline from D-galactosamine hepatitis involves the early activation of ROS-eliminating pathway in the liver

The oral pre-administration of proline, one on the non-essential amino acids, has been shown to effectively protect the liver from D-galactosamine (GalN)-induced liver injury and dramatically improve the survival rate. In the previous study, we reported that protective effect of proline involves the early activation of IL-6/STAT-3 pathway, an anti-inflammatory and regenerative signaling in the liver. Reactive oxygen species (ROS) are mediator of cellular injury and play an important role in hepatic damage during GalN-induced hepatitis. The aim of this study is to investigate the effect of proline on ROS-eliminating system. The activities of major ROS-detoxifying enzymes, i.e., glutathione peroxidase (GP), glutathione reductase (GR), catalase, and the level of glutathione in the liver were determined. Catalase activity was significantly upregulated in proline group from 0 to 3 h after GalN-injection, although GP and GR were downregulated during this period, compared with control group. From 6 to 12 h, the level of reduced glutathione (GSH) was significantly higher and the ratio of GSH/oxidized glutathione (GSSG) tended to be higher in proline group. Consistently with this, at 6 h, the GR activity in the proline group was significantly higher, followed with the higher tendency of GP activity at 12 h. Catalase activity was also significantly higher at 12 h. Taken together, catalase was activated at the beginning, followed with the significant activation of glutathione redox system around 6 to 12 h in proline group. These results suggest that the elimination of ROS in the liver was accelerated in proline group compared with control group at the very early stage of GalN-induced hepatitis.

Gut Microbiota and Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a common complication of liver diseases such as those related to viral hepatitis and liver cirrhosis. The gut-liver axis is gaining increasing attention as a key pathophysiological mechanism responsible for the progression of HCC. Here, we will review the data from the published literature to address the association between HCC and gut microbiota.

SUMMARY

The presence of high levels of endotoxemia in the blood results in portal hypertension and ensuing hepatocyte damage, thus leading to the development of HCC. Probiotics can be used to treat or prevent the progression of HCC, because they may decrease the counts of gut microbiota and thus improve the endotoxemia.

KEY MESSAGE

Increased bacterial translocation can result in endotoxemia, which may play a critical role in the progression of HCC. Modulation of the gut microbiota by probiotics may represent a new avenue for therapeutic intervention in HCC.

PRACTICAL IMPLICATIONS

Breakdown in intestinal barrier function and bacterial overgrowth are main events in the development of HCC. When the intestinal barrier function is disrupted, large amounts of bacterial products can enter the liver and induce inflammation through their receptors, leading to liver diseases. Altering the gut microflora has been proposed as an adjunctive therapy to reduce bacterial translocation and prevent progression of HCC. The purpose of this review is to discuss the relationship between gut microbiota and HCC in both pathogenesis and treatment by probiotics.

Role of gut barrier function in the pathogenesis of nonalcoholic Fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common forms of chronic liver disease, and its incidence is increasing year by year. Many efforts have been made to investigate the pathogenesis of this disease. Since 1998 when Marshall proposed the conception of "gut-liver axis," more and more researchers have paid close attention to the role of gut barrier function in the pathogenesis of NAFLD. The four aspects of gut barrier function, including physical, chemical, biological, and immunological barriers, are interrelated closely and related to NAFLD. In this paper, we present a summary of research findings on the relationship between gut barrier dysfunction and the development of NAFLD, aiming at illustrating the role of gut barrier function in the pathogenesis of this disease.

Protective effects of garcinol in mice with lipopolysaccharide/D-galactosamine-induced apoptotic liver injury

Garcinol is a polyisoprenylated benzophenone derivative of Garcinia indica. Recent researches have revealed the antioxidant, anticancer and anti-inflammatory properties of garcinol. In the present study, the pharmacological effects of garcinol in lipopolysaccharide (LPS)-induced hepatic injury in D-galactosamine (D-Gal)-sensitized mice were investigated. We found that treatment with garcinol significantly decreased serum ALT and AST levels in LPS/D-Gal-exposed mice. These were accomplished with improved histological alterations in liver sections and reduced malondialdehyde (MDA) content in liver homogenates. Garcinol significantly reduced the acetylation level of NF-κB, but it had no obvious effects on the elevation of TNF-α or IL-6 in plasma or liver tissue. Garcinol significantly attenuated LPS/D-Gal-induced hepatic apoptosis as evidenced by reduced number of TUNEL-positive cells in liver sections. Our experiments also showed that garcinol markedly suppressed the cleavage of caspase-3 and significantly decreased the activities of caspase-3, -8, and -9 in liver tissues. In addition, garcinol obviously reduced the induction of Bax but did not alter the level of Bcl-2. These results indicated that garcinol might provide protective benefits in LPS/D-Gal-induced liver injury through suppressing apoptosis.

A plant kavalactone desmethoxyyangonin prevents inflammation and fulminant hepatitis in mice

Alpinia pricei Hayata is a Formosan plant which has been popularly used as nutraceutical or folk medicine for inflammation and various disorders. An active compound of the plant rhizomes, desmethoxyyangonin (DMY), was identified in this study for its novel effect against endotoxin lipopolysaccharide (LPS)-stimulated inflammation in murine macrophages and LPS/D-galactosamine (LPS/D-GalN)-induced fulminant hepatitis in mice. DMY was observed to significantly inhibit proliferation and activation of T cells ex vivo and the activity of several pro-inflammatory mediators in vitro. DMY also protected LPS/D-GalN−induced acute hepatic damages in mice through inhibiting aminotransferases activities and infiltrations of inflammatory macrophages, neutrophils and pathogenic T cells into the liver tissues. In addition, pretreatment with DMY significantly improved the survival rate of LPS/D-GalN−treated mice to 90% (9/10), compared to LPS/D-GalN−treated group (40%, 4/10). UPLC/MS platform-based comparative metabolomics approach was used to explore the serum metabolic profile in fulminant hepatic failure (FHF) mice with or without the DMY pretreatment. The results showed that LPS/D-GalN−induced hepatic damage is likely through perturbing amino acid metabolism, which leads to decreased pyruvate formation via catalysis of aminotransferases, and DMY treatment can prevent to a certain degree of these alterations in metabolic network in mouse caused by LPS/D-GalN. Mechanistic investigation demonstrated that DMY protects LPS or LPS/D-GalN−induced damages in cell or liver tissues mainly through de-regulating IKK/NFκB and Jak2/STAT3 signaling pathways. This report provides evidence-based knowledge to support the rationale for the use of A. pricei root extract in anti-inflammation and also its new function as hepatoprotetive agent against fulminant hepatitis.

Bone marrow and nonbone marrow Toll like receptor 4 regulate acute hepatic injury induced by endotoxemia

Background

Toll-like receptors (TLRs) are expressed in immune cells and hepatocytes. We examined whether hepatic Toll-like receptor 4 (TLR4) is involved in the acute hepatic injury caused by the administration of lipopolysaccharide (LPS) (septic shock model).

Methods

Wild type (WT), TLR4-deficient and chimera mice underwent myeloablative bone marrow transplantation to dissociate between TLR4 expression in the liver or in the immune-hematopoietic system. Mice were injected with LPS and sacrificed 4 hours later.

Results

Compared to TLR4 deficient mice, WT mice challenged with LPS displayed increased serum liver enzymes and hepatic cellular inflammatory infiltrate together with increased serum and hepatic levels of interleukin 1β (IL-1β), tumor necrosis factor α (TNFα) ,Up-regulation of hepatic mRNA encoding TLR4, IκB and c-jun expressions. TLR4 mutant mice transplanted with WT bone marrow were more protected than WT chimeric mice bearing TLR4 mutant hemopoietic cells from LPS, as seen by IL-1β and TNFα levels. We then used hepatocytes (Huh7) and macrophages from monocytic cell lines to detect TLR mRNA expression. Macrophages expressed a significantly higher level of TLR4 mRNA and TLR2 (more than 3000- and 8000-fold respectively) compared with the hepatocyte cell line. LPS administration induced TLR4 activation in a hepatocyte cell line in a dose dependent manner while TLR2 mRNA hardly changed.

Conclusions

These results suggest that TLR4 activation of hepatocytes participate in the immediate response to LPS induced hepatic injury. However, in this response, the contribution of TLR4 on bone marrow derived cells is more significant than those of the hepatocytes. The absence of the TLR4 gene plays a pivotal role in reducing hepatic LPS induced injury.

Genomic instability in liver cells caused by an LPS-induced bystander-like effect

Bacterial infection has been linked to carcinogenesis, however, there is lack of knowledge of molecular mechanisms that associate infection with the development of cancer. We analyzed possible effects of the consumption of heat-killed E. coli O157:H7 cells or its cellular components, DNA, RNA, protein or lipopolysaccharides (LPS) on gene expression in naïve liver cells. Four week old mice were provided water supplemented with whole heat-killed bacteria or bacterial components for a two week period. One group of animals was sacrificed immediately, whereas another group was allowed to consume uncontaminated tap water for an additional two weeks, and liver samples were collected, post mortem. Liver cells responded to exposure of whole heat-killed bacteria and LPS with alteration in γH2AX levels and levels of proteins involved in proliferation, DNA methylation (MeCP2, DNMT1, DNMT3A and 3B) or DNA repair (APE1 and KU70) as well as with changes in the expression of genes involved in stress response, cell cycle control and bile acid biosynthesis. Other bacterial components analysed in this study did not lead to any significant changes in the tested molecular parameters. This study suggests that lipopolysaccharides are a major component of Gram-negative bacteria that induce molecular changes within naïve cells of the host.

Microbial translocation in the pathogenesis of HIV infection and AIDS

In pathogenic simian immunodeficiency virus (SIV) and human immunodeficiency virus (HIV) infections, the translocation of microbial products from the gastrointestinal (GI) tract to portal and systemic circulation has been proposed as a major driver of the chronic immune activation that is associated with disease progression. Consistently, microbial translocation is not present in nonpathogenic SIV infections of natural host species. In vivo studies demonstrated that HIV/SIV-associated microbial translocation results from a series of immunopathological events occurring at the GI mucosa: (i) early and severe mucosal CD4(+) depletion, (ii) mucosal immune hyperactivation/persistent inflammation; (iii) damage to the integrity of the intestinal epithelium with enterocyte apoptosis and tight junction disruption; and (iv) subverted the gut microbiome, with a predominance of opportunistic bacteria. Direct in situ evidence of microbial translocation has been provided for SIV-infected rhesus macaques showing translocated microbial products in the intestinal lamina propria and distant sites. While the mechanisms by which microbial translocation causes immune activation remain controversial, a key pathogenic event appears to be innate immunity activation via Toll-like receptors and other pathogen recognition receptors. Accumulating clinical observations suggest that microbial translocation might affect HIV disease progression, response to therapy, and non-AIDS comorbidities. Given its detrimental effect on overall immunity, several interventions to prevent/block microbial translocation are currently under investigation as novel therapeutic agents for HIV/AIDS.

Altered functionality of anti-bacterial antibodies in patients with chronic hepatitis C virus infection

Background

Using comparative glycoproteomics, we have previously identified a glycoprotein that is altered in both amount and glycosylation as a function of liver cirrhosis. The altered glycoprotein is an agalactosylated (G0) immunoglobulin G molecule (IgG) that recognizes the heterophilic alpha-gal epitope. Since the alpha gal epitope is found on gut enterobacteria, it has been hypothesized that anti-gal antibodies are generated as a result of increased bacterial exposure in patients with liver disease.

Methods

The N-linked glycosylation of anti-gal IgG molecules from patients with fibrosis and cirrhosis was determined and the effector function of anti-bacterial antibodies from over 100 patients examined. In addition, markers of microbial exposure were determined.

Results

Surprisingly, the subset of agalactosylated anti-gal antibodies described here, was impaired in their ability to mediate complement mediated lysis and inhibited the complement-mediated destruction of common gut bacteria. In an analysis of serum from more than 100 patients with liver disease, we have shown that those with increased levels of this modified anti-gal antibody had increased levels of markers of bacterial exposure.

Conclusions

Anti-gal antibodies in patients with liver cirrhosis were reduced in their ability to mediate complement mediated lysis of target cells. As bacterial infection is a major complication in patients with cirrhosis and bacterial products such as LPS are thought to play a major role in the development and progression of liver fibrosis, this finding has many clinical implications in the etiology, prognosis and treatment of liver disease.

Chronic immune activation in common variable immunodeficiency (CVID) is associated with elevated serum levels of soluble CD14 and CD25 but not endotoxaemia

Common variable immunodeficiency (CVID), the most frequent symptomatic immunoglobulin primary immunodeficiency, is associated with chronic T cell activation and reduced frequency of CD4(+) T cells. The underlying cause of immune activation in CVID is unknown. Microbial translocation indicated by elevated serum levels of lipopolysaccharide and soluble CD14 (sCD14) has been linked previously to systemic immune activation in human immunodeficiency virus/acquired immune deficiency syndrome (HIV-1/AIDS), alcoholic cirrhosis and other conditions. To address the mechanisms of chronic immune activation in CVID, we performed a detailed analysis of immune cell populations and serum levels of sCD14, soluble CD25 (sCD25), lipopolysaccharide and markers of liver function in 35 patients with CVID, 53 patients with selective immunoglobulin (Ig)A deficiency (IgAD) and 63 control healthy subjects. In CVID subjects, the concentration of serum sCD14 was increased significantly and correlated with the level of sCD25, C-reactive protein and the extent of T cell activation. Importantly, no increase in serum lipopolysaccharide concentration was observed in patients with CVID or IgAD. Collectively, the data presented suggest that chronic T cell activation in CVID is associated with elevated levels of sCD14 and sCD25, but not with systemic endotoxaemia, and suggest involvement of lipopolysaccharide-independent mechanisms of induction of sCD14 production.

Ron receptor-dependent gene regulation in a mouse model of endotoxin-induced acute liver failure

BACKGROUND

Prior experimentation has shown that loss of the tyrosine kinase (TK) signaling domain of the Ron receptor leads to marked hepatocyte protection in a model of lipopolysaccharide-induced acute liver failure (ALF) in D-galactosamine (GalN)-sensitized mice. The aim of this study was to identify the role of Ron in the regulation of hepatic gene expression.

METHODS

Microarray analyses were performed on liver RNA isolated sequentially from wild-type (WT) and TK-/- mice during the progression of ALF. Gene array data were validated using Western and immunohistochemistry analyses as well as with ex vivo culture systems.

RESULTS

At baseline, 101 genes were differentially expressed between WT and TK-/- livers, which regulate processes involved in hypoxia, proliferation, apoptosis and metabolism. One hour after ALF induction, WT livers exhibited increased cytokine expression compared to TK-/- livers, and after 4 hours, an induction of suppressor of cytokine signaling (SOCS) genes as well as JAK-STAT pathway activation were prominent in TK-/- livers compared to controls.

CONCLUSION

Our studies suggest a novel hepato-protective mechanism in Ron TK-/- mice wherein increased and sustained SOCS production and JAK-STAT activation in the hepatocyte may inhibit the destructive proinflammatory milieu and promote survival factors which blunt hepatic death and the ensuing development of ALF.

Microbial translocation in HIV infection: causes, consequences and treatment opportunities

Systemic immune activation is increased in HIV-infected individuals, even in the setting of virus suppression with antiretroviral therapy. Although numerous factors may contribute, microbial products have recently emerged as potential drivers of this immune activation. In this Review, we describe the intestinal damage that occurs in HIV infection, the evidence for translocation of microbial products into the systemic circulation and the pathways by which these products activate the immune system. We also discuss novel therapies that disrupt the translocation of microbial products and the downstream effects of microbial translocation.

Dietary supplementation with geranylgeraniol suppresses lipopolysaccharide-induced inflammation via inhibition of nuclear factor-κB activation in rats

PURPOSE

The isoprenoid geranylgeraniol (GGOH) inhibits nuclear factor-kappa B (NF-κB) activation in the liver, yet the mechanism remains unclear. We investigated the modulation and inhibition of lipopolysaccharide (LPS)-induced NF-κB signaling in the liver of rats fed a GGOH-supplemented diet.

METHODS

Rats were fed a diet supplemented with or without GGOH for 10 days. Rats were then intraperitoneally injected with 0.5 mg/kg LPS or vehicle (sterilized saline) and fasted for 18 h. Plasma levels of the inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, and the liver damage indicators alanine and aspartate aminotransferases (ALT and AST) were assessed. Liver mRNA and proteins were assayed for changes in NF-κB target genes and signal transduction genes.

RESULTS

Rats fed a high-dose, GGOH-supplemented diet showed significantly lower levels of plasma inflammatory cytokines and ALT and AST activities. In the liver, GGOH significantly suppressed NF-κB activation and mRNA expression of its pro-inflammatory target genes. Furthermore, GGOH supplementation substantially suppressed mRNA expression of signal transducer genes upstream of the IκB kinase complex. Western blotting of liver extracts further demonstrated the substantial decrease in total IL-1 receptor-associated kinase 1 (IRAK1) and TNF receptor-associated factor 6 (TRAF6), leading to lower signal transduction and inhibition of NF-κB after LPS.

CONCLUSION

A 10-day, high-dose, GGOH-supplemented diet was sufficient to inhibit LPS-induced inflammation and activation of NF-κB in rat livers. GGOH significantly modulated NF-κB signaling molecules, inhibiting its signal transduction and activation in the liver, thus protecting against liver damage.

The role of innate immunity in HBV infection

Hepatitis B virus (HBV) infection is one of the main causes of chronic liver diseases. Whether HBV infection is cleared or persists is determined by both viral factors and host immune responses. It becomes clear that innate immunity is of importance in protecting the host from HBV infection and persistence. However, HBV develops strategies to suppress the antiviral immune responses. A combined therapeutic strategy with both viral suppression and enhancement of antiviral immune responses is needed for effective long-term clearance and cure for chronic HBV infection. We and others confirmed that bifunctional siRNAs with both gene silencing and innate immune activation properties are beneficial for inhibition of HBV and represent a potential approach for treatment of viral infection. Understanding the nature of liver innate immunity and their roles in chronic HBV progression and HBV clearance may aid in the design of novel therapeutic strategies for chronic HBV infection.

Rifaximin, but not growth factor 1, reduces brain edema in cirrhotic rats

AIM: To compare rifaximin and insulin-like growth factor (IGF)-1 treatment of hyperammonemia and brain edema in cirrhotic rats with portal occlusion.

METHODS: Rats with CCl₄-induced cirrhosis with ascites plus portal vein occlusion and controls were randomized into six groups: Cirrhosis; Cirrhosis + IGF-1; Cirrhosis + rifaximin; Controls; Controls + IGF-1; and Controls + rifaximin. An oral glutamine-challenge test was performed, and plasma and cerebral ammonia, glucose, bilirubin, transaminases, endotoxemia, brain water content and ileocecal cultures were measured and liver histology was assessed.

RESULTS: Rifaximin treatment significantly reduced bacterial overgrowth and endotoxemia compared with cirrhosis groups, and improved some liver function parameters (bilirubin, alanine aminotransferase and aspartate aminotransferase). These effects were associated with a significant reduction in cerebral water content. Blood and cerebral ammonia levels, and area-under-the-curve values for oral glutamine-challenge tests were similar in rifaximin-treated cirrhotic rats and control group animals. By contrast, IGF-1 administration failed to improve most alterations observed in cirrhosis.

CONCLUSION: By reducing gut bacterial overgrowth, only rifaximin was capable of normalizing plasma and brain ammonia and thereby abolishing low-grade brain edema, alterations associated with hepatic encephalopathy.