Upregulation of TNF-alpha production signaling pathways in monocytes from patients with advanced cirrhosis: possible role of Akt and IRAK-M

The Pathophysiology of Portal Hypertension

This article reviews the pathophysiology of portal hypertension that includes multiple mechanisms internal and external to the liver. This article starts with a review of literature describing the cellular and molecular mechanisms of portal hypertension, microvascular thrombosis, sinusoidal venous congestion, portal angiogenesis, vascular hypocontractility, and hyperdynamic circulation. Mechanotransduction and the gut-liver axis, which are newer areas of research, are reviewed. Dysfunction of this axis contributes to chronic liver injury, inflammation, fibrosis, and portal hypertension. Sequelae of portal hypertension are discussed in subsequent studies.

Elevated CD169 expressing monocyte/macrophage promotes systemic inflammation and disease progression in cirrhosis

Systemic inflammation is related to disease progression and prognosis in patients with advanced cirrhosis. However, the mechanisms underlying the initiation of inflammation are still not fully understood. The role of CD169+ monocyte/macrophage in cirrhotic systemic inflammation was undetected. Flow cytometry analysis was used to detect the percentage and phenotypes of CD169+ monocytes as well as their proinflammatory function in patient-derived cirrhotic tissue and blood. Transcriptome differences between CD169+ and CD169- monocytes were also compared. Additionally, a mouse model with specific depletion of CD169+ monocytes/macrophages was utilized to define their role in liver injury and fibrosis. We observed increased CD169 expression in monocytes from cirrhotic patients, which was correlated with inflammatory cytokine production and disease progression. CD169+ monocytes simultaneously highly expressed M1- and M2-like markers and presented immune-activated profiles. We also proved that CD169+ monocytes robustly prevented neutrophil apoptosis. Depletion of CD169+ monocytes/macrophages significantly inhibited inflammation and liver necrosis in acute liver injury, but the spontaneous fibrin resolution after repeated liver injury was impaired. Our results indicate that CD169 defines a subset of inflammation-associated monocyte that correlates with disease development in patients with cirrhosis. This provides a possible therapeutic target for alleviating inflammation and improving survival in cirrhosis.

Mevinphos induces developmental defects via inflammation, apoptosis, and altered MAPK and Akt signaling pathways in zebrafish

Mevinphos, an organophosphate insecticide, is widely used to control pests and enhance crop yield. Because of its high solubility, it can easily flow into water and threaten the aquatic environment, and it is known to be hazardous to non-target organisms. However, little is known about its developmental toxicity and the underlying toxic mechanisms. In this study, we utilized zebrafish, which is frequently used for toxicological research to estimate the toxicity in other aquatic organisms or vertebrates including humans, to elucidate the developmental defects induced by mevinphos. Here, we observed that mevinphos induced various phenotypical abnormalities, such as diminished eyes and head sizes, shortened body length, loss of swim bladder, and increased pericardiac edema. Also, exposure to mevinphos triggered inflammation, apoptosis, and DNA fragmentation in zebrafish larvae. In addition, MAPK and Akt signaling pathways, which control apoptosis, inflammation, and proper development of various organs, were also altered by the treatment of mevinphos. Furthermore, these factors induced various organ defects which were confirmed by various transgenic models. We identified neuronal toxicity through transgenic olig2:dsRed zebrafish, cardiovascular toxicity through transgenic fli1:eGFP zebrafish, and hepatotoxicity and pancreatic toxicity through transgenic lfabp:dsRed;elastase:GFP zebrafish. Overall, our results elucidated the developmental toxicities of mevinphos in zebrafish and provided the parameters for the assessment of toxicities in aquatic environments.

Is it possible to intervene early cirrhosis by targeting toll-like receptors to rebalance the intestinal microbiome?

Cirrhosis is a progressive chronic liver disease caused by one or more causes and characterized by diffuse fibrosis, pseudolobules, and regenerated nodules. Once progression to hepatic decompensation, the function of the liver and other organs is impaired and almost impossible to reverse and recover, which often results in hospitalization, impaired quality of life, and high mortality. However, in the early stage of cirrhosis, there seems to be a possibility of cirrhosis reversal. The development of cirrhosis is related to the intestinal microbiota and activation of toll-like receptors (TLRs) pathways, which could regulate cell proliferation, apoptosis, expression of the hepatomitogen epiregulin, and liver inflammation. Targeting regulation of intestinal microbiota and TLRs pathways could affect the occurrence and development of cirrhosis and its complications. In this paper, we first reviewed the dynamic change of intestinal microbiota and TLRs during cirrhosis progression. And further discussed the interaction between them and potential therapeutic targets to reverse early staged cirrhosis.

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.

Portopulmonary Hypertension: A Review of the Current Literature

Portopulmonary hypertension is defined as the development of pulmonary arterial hypertension in the setting of portal hypertension with or without liver cirrhosis. Portal hypertension-associated haemodynamic changes, including hyperdynamic state, portosystemic shunts and splanchnic vasodilation, induce significant alterations in pulmonary vascular bed and play a pivotal role in the pathogenesis of the disease. If left untreated, portopulmonary hypertension results in progressive right heart failure, with a poor prognosis. Although Doppler echocardiography is the best initial screening tool for symptomatic patients and liver transplantation candidates, right heart catheterisation remains the gold standard for the diagnosis of the disease. Severe portopulmonary hypertension exerts a prohibitive risk to liver transplantation by conferring an elevated perioperative mortality risk. It is important for haemodynamic parameters to correspond with non-severe portopulmonary hypertension before patients can proceed with the liver transplantation. Small uncontrolled studies and a recent randomised controlled trial have reported promising results with vasodilatory therapies in clinical and haemodynamic improvement of patients, allowing a proportion of patients to undergo liver transplantation. In this review, the epidemiology, pathogenesis, diagnostic approach and management of portopulmonary hypertension are discussed. We also highlight fields of ongoing investigation pertinent to risk stratification and optimal patient selection to maximise long-term benefit from currently available treatments.

Cirrhosis-associated immune dysfunction

The term cirrhosis-associated immune dysfunction (CAID) comprises the distinctive spectrum of immune alterations associated with the course of end-stage liver disease. Systemic inflammation and immune deficiency are the key components of CAID. Their severity is highly dynamic and progressive, paralleling cirrhosis stage. CAID involves two different immune phenotypes: the low-grade systemic inflammatory phenotype and the high-grade systemic inflammatory phenotype. The low-grade systemic inflammatory phenotype can be found in patients with compensated disease or clinical decompensation with no organ failure. In this phenotype, there is an exaggerated immune activation but the effector response is not markedly compromised. The high-grade systemic inflammatory phenotype is present in patients with acute-on-chronic liver failure, a clinical situation characterized by decompensation, organ failure and high short-term mortality. Along with high-grade inflammation, this CAID phenotype includes intense immune paralysis that critically increases the risk of infections and worsens prognosis. The intensity of CAID has important consequences on cirrhosis progression and correlates with the severity of liver insufficiency, bacterial translocation and organ failure. Therapies targeting the modulation of the dysfunctional immune response are currently being evaluated in preclinical and clinical studies.

Outcomes of septic cirrhosis patients admitted to the intensive care unit: A retrospective cohort study

The aim of this study is to examine the outcome of septic patients with cirrhosis admitted to the intensive care unit (ICU) and predictors of mortality.Single center, retrospective cohort study.The study was conducted in Intensive care Department of King Abdulaziz Medical City, Riyadh, Saudi Arabia.Data was extracted from a prospectively collected ICU database managed by a full time data collector. All patients with an admission diagnosis of sepsis according to the sepsis-3 definition were included from 2002 to 2017. Patients were categorized into 2 groups based on the presence or absence of cirrhosis.The primary outcome of the study was in-hospital mortality. Secondary outcomes included ICU mortality, ICU and hospital lengths of stay and mechanical ventilation duration.A total of 7906 patients were admitted to the ICU with sepsis during the study period, of whom 497 (6.29%) patients had cirrhosis. 64.78% of cirrhotic patients died during their hospital stay compared to 31.54% of non-cirrhotic. On multivariate analysis, cirrhosis patients were at greater odds of dying within their hospital stay as compared to non-cirrhosis patients (Odds ratio {OR} 2.53; 95% confidence interval {CI} 2.04 - 3.15) independent of co-morbidities, organ dysfunction or hemodynamic status. Among cirrhosis patients, elevated international normalization ratio (INR) (OR 1.69; 95% CI 1.29-2.23), hemodialysis (OR 3.09; 95% CI 1.76-5.42) and mechanical ventilation (OR 2.61; 95% CI 1.60-4.28) were the independent predictors of mortality.Septic cirrhosis patients admitted to the intensive care unit have greater odds of dying during their hospital stay. Among septic cirrhosis patients, elevated INR and the need for hemodialysis and mechanical ventilation were associated with increased mortality.

A New Murine Liver Fibrosis Model Induced by Polyhexamethylene Guanidine-Phosphate

Liver fibrosis is part of the wound healing process to help the liver recover from the injuries caused by various liver-damaging insults. However, liver fibrosis often progresses to life-threatening cirrhosis and hepatocellular carcinoma. To overcome the limitations of current in vivo liver fibrosis models for studying the pathophysiology of liver fibrosis and establishing effective treatment strategies, we developed a new mouse model of liver fibrosis using polyhexamethylene guanidine phosphate (PHMG-p), a humidifier sterilizer known to induce lung fibrosis in humans. Male C57/BL6 mice were intraperitoneally injected with PHMG-p (0.03% and 0.1%) twice a week for 5 weeks. Subsequently, liver tissues were examined histologically and RNA-sequencing was performed to evaluate the expression of key genes and pathways affected by PHMG-p. PHMG-p injection resulted in body weight loss of ~15% and worsening of physical condition. Necropsy revealed diffuse fibrotic lesions in the liver with no effect on the lungs. Histology, collagen staining, immunohistochemistry for smooth muscle actin and collagen, and polymerase chain reaction analysis of fibrotic genes revealed that PHMG-p induced liver fibrosis in the peri-central, peri-portal, and capsule regions. RNA-sequencing revealed that PHMG-p affected several pathways associated with human liver fibrosis, especially with upregulation of lumican and IRAK3, and downregulation of GSTp1 and GSTp2, which are closely involved in liver fibrosis pathogenesis. Collectively we demonstrated that the PHMG-p-induced liver fibrosis model can be employed to study human liver fibrosis.

Exaggerated Microvascular Vasodilating Responses in Cirrhotic Patients With Septic Shock

OBJECTIVES

Cirrhosis is associated with hemodynamic and vascular disorders. However, microvascular reactivity of cirrhotic patients in the context of sepsis has poorly been investigated.

DESIGN

Prospective observational study.

SETTING

Medical ICU in a tertiary teaching hospital.

PATIENTS

We prospectively included adult patients admitted in the ICU for septic shock with and without cirrhosis. After initial resuscitation, global hemodynamic parameters were recorded and skin microvascular reactivity to local acetylcholine iontophoresis was measured.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thirty patients with septic shock were included (60% male), 10 with cirrhosis and 20 without, with a median age of 61 years (54-74 yr). Cirrhotic patients were mainly classed as Child-Pugh C (80%) and all of them had ascites. Sequential Organ Failure Assessment score and ICU mortality of cirrhotic patients were higher than the noncirrhotic patients, respectively (6.5 [5.0-8.3] vs 11.5 [9.0-14.0]; p < 0.01; 15% vs 70%; p < 0.01). Peripheral tissue perfusion and global hemodynamic parameters were not different between the cirrhotic and noncirrhotic patients but arterial lactate level was three times higher in patients with cirrhosis (6.0 mmol/L [3.9-8.0 mmol/L] vs 2.0 mmol/L [0.9-3.5 mmol/L]; p < 0.01). Basal skin microvascular blood flow was not statistically different between the groups (4.94 perfusion units [3.45-8.73 perfusion units] vs 6.95 perfusion units [5.24-8.38 perfusion units]; p = 0.29). After acetylcholine simulation, skin microvascular blood flow increased more in cirrhotic patients than in noncirrhotic patients (644% [217-966%] vs 169% [73-505%], p = 0.03). Global microvascular reactivity was seven times higher in cirrhotic patients (area under the curve, 16,412 perfusion units [13,898-19,041 perfusion units] vs 2,664 perfusion units [969-4,604 perfusion units]; p < 0.001).

CONCLUSIONS

We identified an exaggerated vasodilating microvascular response in cirrhotic patients with septic shock. Such a result may explain vasopressor resistance and paves the way for future therapeutic trials, targeting nitric oxide pathway specifically in this population.

Analysis of interleukin-1 receptor associated kinase-3 (IRAK3) function in modulating expression of inflammatory markers in cell culture models: A systematic review and meta-analysis

BACKGROUND

IRAK3 is a critical modulator of inflammation in innate immunity. IRAK3 is associated with many inflammatory diseases, including sepsis, and is required in endotoxin tolerance to maintain homeostasis of inflammation. The impact of IRAK3 on inflammatory markers such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cell culture models remains controversial.

OBJECTIVE

To analyse temporal effects of IRAK3 on inflammatory markers after one- or two-challenge interventions in cell culture models.

METHODS

A systematic search was performed to identify in vitro cell studies reporting outcome measures of expression of IRAK3 and inflammatory markers. Meta-analyses were performed where sufficient data were available. Comparisons of outcome measures were performed between different cell lines and human and mouse primary cells.

RESULTS

The literature search identified 7766 studies for screening. After screening titles, abstracts and full-texts, a total of 89 studies were included in the systematic review.

CONCLUSIONS

The review identifies significant effects of IRAK3 on decreasing NF-κB DNA binding activity in cell lines, TNF-α protein level at intermediate time intervals (4h-15h) in cell lines or at long term intervals (16h-48h) in mouse primary cells following one-challenge. The patterns of TNF-α protein expression in human cell lines and human primary cells in response to one-challenge are more similar than in mouse primary cells. Meta-analyses confirm a negative correlation between IRAK3 and inflammatory cytokine (IL-6 and TNF-α) expression after two-challenges.

The immunological roles in acute-on-chronic liver failure: An update

BACKGROUND

Acute-on-chronic liver failure (ACLF) refers to the acute deterioration of liver function that occurs in patients with chronic liver disease. ACLF is characterized by acute decompensation, organ failure and high short-term mortality. Numerous studies have been conducted and remarkable progress has been made regarding the pathophysiology and pathogenesis of this disease in the last decade. The present review was to summarize the advances in this field.

DATA SOURCES

A comprehensive search in PubMed and EMBASE was conducted using the medical subject words "acute-on-chronic liver failure", "ACLF", "pathogenesis", "predictors", and "immunotherapy" combined with free text terms such as "systemic inflammation" and "immune paralysis". Relevant papers published before October 31, 2018, were included.

RESULTS

ACLF has two marked pathophysiological features, namely, excessive systemic inflammation and susceptibility to infection. The systemic inflammation is mainly manifested by a significant increase in the levels of plasma pro-inflammatory factors, leukocyte count and C-reactive protein. The underlying mechanisms are unclear and may be associated with decreased immune inhibitory cells, abnormal expression of cell surface molecules and intracellular regulatory pathways in immune cells and increased damage-associated molecular patterns in circulation. However, the main cause of susceptibility to infection is immune paralysis. Immunological paralysis is characterized by an attenuated activity of immune cells. The mechanisms are related to elevations of immune inhibitory cells and the concentration of plasma anti-inflammatory molecules. Some immune biological indicators, such as soluble CD163, are used to explore the pathogenesis and prognosis of the disease, and some immunotherapies, such as glucocorticoids and granulocyte colony-stimulating factor, are effective on ACLF.

CONCLUSIONS

Overwhelming systemic inflammation and susceptibility to infection are two key features of ACLF. A better understanding of the state of a patient's immune system will help to guide immunotherapy for ACLF.

Regulation of Monocyte-Macrophage Responses in Cirrhosis-Role of Innate Immune Programming and Checkpoint Receptors

Many aspects of the innate immune system have been studied in cirrhosis, and abnormalities have been described supporting both a pro-inflammatory and anti-inflammatory phenotype of myeloid cells. However, the findings of these studies vary by stage of disease and methodology. The recent description of the syndrome of acute-on-chronic liver failure (ACLF) has refined our understanding of the natural history of cirrhosis. In this context, we review the regulatory mechanisms at play that contribute to the immune abnormalities described in advanced liver disease. Specifically, we review the evidence for epigenetic mechanisms regulating monocyte phenotype, and the role of checkpoint receptors on regulating innate and adaptive immune cell function.

Photocrosslinkable Gelatin Hydrogels Modulate the Production of the Major Pro-inflammatory Cytokine, TNF-α, by Human Mononuclear Cells

Hydrogels are an attractive class of biomaterials in tissue engineering due to their inherently compatible properties for cell culture. Gelatin methacryloyl (GelMA) has shown significant promise in the fields of tissue engineering and drug delivery, as its physical properties can be precisely tuned depending on the specific application. There is a growing appreciation for the interaction between biomaterials and cells of the immune system with the increasing usage of biomaterials for in vivo applications. Here, we addressed the current lack of information regarding the immune-modulatory properties of photocrosslinked GelMA. We investigated the ability of human mononuclear cells to mount inflammatory responses in the context of a GelMA hydrogel platform. Using lipopolysaccharide to stimulate a pro-inflammatory immune response, we found tumor necrosis factor-α (TNF-α) expression was suppressed in GelMA culture conditions. Our findings have important implications on the future use of GelMA, and potentially similar hydrogels, and highlight the significance of investigating the potential immune-modulatory properties of biomaterials.

Cancer; an induced disease of twentieth century! Induction of tolerance, increased entropy and 'Dark Energy': loss of biorhythms (Anabolism v. Catabolism)

Maintenance of health involves a synchronized network of catabolic and anabolic signals among organs/tissues/cells that requires differential bioenergetics from mitochondria and glycolysis (biological laws or biorhythms). We defined biological circadian rhythms as Yin (tumoricidal) and Yang (tumorigenic) arms of acute inflammation (effective immunity) involving immune and non-immune systems. Role of pathogens in altering immunity and inducing diseases and cancer has been documented for over a century. However, in 1955s decision makers in cancer/medical establishment allowed public (current baby boomers) to consume million doses of virus-contaminated polio vaccines. The risk of cancer incidence and mortality sharply rose from 5% (rate of hereditary/genetic or innate disease) in 1900s, to its current scary status of 33% or 50% among women and men, respectively. Despite better hygiene, modern detection technologies and discovery of antibiotics, baby boomers and subsequent 2–3 generations are sicker than previous generations at same age. American health status ranks last among other developed nations while America invests highest amount of resources for healthcare. In this perspective we present evidence that cancer is an induced disease of twentieth century, facilitated by a great deception of cancer/medical establishment for huge corporate profits. Unlike popularized opinions that cancer is 100, 200 or 1000 diseases, we demonstrate that cancer is only one disease; the severe disturbances in biorhythms (differential bioenergetics) or loss of balance in Yin and Yang of effective immunity. Cancer projects that are promoted and funded by decision makers are reductionist approaches, wrong and unethical and resulted in loss of millions of precious lives and financial toxicity to society. Public vaccination with pathogen-specific vaccines (e.g., flu, hepatitis, HPV, meningitis, measles) weakens, not promotes, immunity. Results of irresponsible projects on cancer sciences or vaccines are increased population of drug-dependent sick society. Outcome failure rates of claimed ‘targeted’ drugs, ‘precision’ or ‘personalized’ medicine are 90% (± 5) for solid tumors. We demonstrate that aging, frequent exposures to environmental hazards, infections and pathogen-specific vaccines and ingredients are ‘antigen overload’ for immune system, skewing the Yin and Yang response profiles and leading to induction of ‘mild’, ‘moderate’ or ‘severe’ immune disorders. Induction of decoy or pattern recognition receptors (e.g., PRRs), such as IRAK-M or IL-1dRs (‘designer’ molecules) and associated genomic instability and over-expression of growth promoting factors (e.g., pyruvate kinases, mTOR and PI3Ks, histamine, PGE2, VEGF) could lead to immune tolerance, facilitating cancer cells to hijack anabolic machinery of immunity (Yang) for their increased growth requirements. Expression of constituent embryonic factors would negatively regulate differentiation of tumor cells through epithelial–mesenchymal-transition and create “dual negative feedback loop” that influence tissue metabolism under hypoxic conditions. It is further hypothesized that induction of tolerance creates ‘dark energy’ and increased entropy and temperature in cancer microenvironment allowing disorderly cancer proliferation and mitosis along with increased glucose metabolism via Crabtree and Pasteur Effects, under mitophagy and ribophagy, conditions that are toxic to host survival. Effective translational medicine into treatment requires systematic and logical studies of complex interactions of tumor cells with host environment that dictate clinical outcomes. Promoting effective immunity (biological circadian rhythms) are fundamental steps in correcting host differential bioenergetics and controlling cancer growth, preventing or delaying onset of diseases and maintaining public health. The author urges independent professionals and policy makers to take a closer look at cancer dilemma and stop the ‘scientific/medical ponzi schemes’ of a powerful group that control a drug-dependent sick society before all hopes for promoting public health evaporate.

Antifibrotic Mechanism of Pinocembrin: Impact on Oxidative Stress, Inflammation and TGF-β /Smad Inhibition in Rats

INTRODUCTION

The present study aimed to elucidate the potential antifibrotic effects of pinocembrin (PIN), a flavanone found abundantly in honey and propolis, by studying its effect on different oxidative stress, inflammatory and fibrosis markers in an experimental model of CCl4-induced liver fibrosis.

MATERIAL AND METHODS

PIN (20 mg/kg) was given orally 3 times/week for 6 consecutive weeks alternating with CCl4 (0.5 mL/kg, 1:1 mixture with corn oil, i. p.) twice weekly. Different hepatotoxicity indices, oxidative stress, inflammatory and liver fibrosis markers were assessed.

RESULTS

PIN significantly restored liver transaminases and total cholesterol to normal levels. Also, PIN ameliorated oxidative stress injury evoked by CCl4 as evidenced by inhibition of reduced glutathione depletion and lipid peroxidation as well as elevation of antioxidant enzyme superoxide dismutase (SOD). Further, PIN upregulated the nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), thereby inducing the expression and activity of the cytoprotective enzyme hemeoxygenase-1 (HO-1). Moreover, PIN alleviated pro-inflammatory cytokines such as TNF-α via inhibiting nuclear factor-κB (NF-κB) activation. As markers of fibrosis, collagen and α-SMA expression increased markedly in the CCl4 group and PIN prevented these alterations. In addition, PIN down-regulated TGFβ1 and p-Smad2/3, thereby inhibiting TGFβ1/Smad signaling pathway.

CONCLUSION

These results suggest that PIN possess potent antifibrotic effects that can be explained on its antioxidant properties. It ameliorates oxidative stress and inflammation during induction of fibrogenesis via its ability to augment celular antioxidant defenses, activating Nrf2-mediated HO-1 expression and modulating NF-κB and TGF-β1/Smad signaling pathway.

Treatment of Type-1 Hepatorenal Syndrome with Pentoxifylline: A Randomized Placebo Controlled Clinical Trial

INTRODUCTION

Type-1 hepatorenal syndrome (HRS-1) portends a poor prognosis in patients with cirrhosis. Currently available medical therapies are largely ineffective, save for liver transplantation. We aimed to determine if pentoxifylline (PTX) therapy in addition to the standard of care of volume expansion with albumin and vasoconstriction with midodrine and octreotide (AMO) is safe and efficacious compared to AMO in HRS-1 treatment.

MATERIAL AND METHODS

Hospitalized subjects with decompensated cirrhosis and HRS-1 were enrolled. PTX or placebo was administered with AMO therapy for up to 14 days. The primary endpoint was HRS-1 resolution (serum creatinine ≤ 1.5 g/dL for &gt; 24 h). Secondary endpoints were change in creatinine and MELD score, partial treatment response, 30-and 180-day overall and transplant free survival.

RESULTS

Twelve subjects with mean age 58.9 ± 6.2 years were enrolled and randomized. Mean MELD score was 26.5 ± 7.4 and 58.3% were male. Overall cohort 30- and 180-day survival was 58.3% and 33.3% respectively. Two subjects underwent liver transplantation. HRS-1 resolution (16.7% vs. 16.7%, p = 1.000), partial treatment response (33.3% vs. 16.7%, p = 0.505), change in creatinine (+0.48 g/dL, 95% CI -0.49-1.46 vs. +0.03 g/dL, 95% CI -0.64- 0.70, p = 0.427), 30-day survival (66.6% vs. 50.0%, p = 0.558) and 180-day survival (50.0% vs. 16.7%, p = 0.221) were similar between the two groups. Serious adverse events necessitating treatment discontinuation were rare (n = 1, PTX).

DISCUSSION

The addition of PTX to AMO in the treatment of HRS-1 is safe when compared to the current standard of care. Future large-scale prospective study to validate the efficacy of this treatment seems warranted.

Management of bacterial infection in the liver transplant candidate

Bacterial infection (BI) is a common cause of impairment of liver function in patients with cirrhosis, especially in the liver transplant candidates. These patients share an immunocompromised state and increased susceptibility to develop community and hospital-acquired infections. The changing epidemiology of BI, with an increase of multidrug resistant strains, especially in healthcare-associated settings, represents a critical issue both in the waiting list and in the post-operative management. This review focused on the role played by BI in patients awaiting liver transplantation, evaluating the risk of drop-out from the waiting list, the possibility to undergo liver transplantation after recovery from infection or during a controlled infection.

Rifaximin has minor effects on bacterial composition, inflammation, and bacterial translocation in cirrhosis: A randomized trial

BACKGROUND AND AIM

Decompensated cirrhosis is characterized by disturbed hemodynamics, immune dysfunction, and high risk of infections. Translocation of viable bacteria and bacterial products from the gut to the blood is considered a key driver in this process. Intestinal decontamination with rifaximin may reduce bacterial translocation (BT) and decrease inflammation. A randomized, placebo-controlled trial investigated the effects of rifaximin on inflammation and BT in decompensated cirrhosis.

METHODS

Fifty-four out-patients with cirrhosis and ascites were randomized, mean age 56 years (± 8.4), and model for end-stage liver disease score 12 (± 3.9). Patients received rifaximin 550-mg BD (n = 36) or placebo BD (n = 18). Blood and fecal (n = 15) sampling were conducted at baseline and after 4 weeks. Bacterial DNA in blood was determined by real-time qPCR 16S rRNA gene quantification. Bacterial composition in feces was analyzed by 16S rRNA gene sequencing.

RESULTS

Circulating markers of inflammation, including tumor necrosis factor alpha, interleukins 6, 10, and 18, stromal cell-derived factor 1-α, transforming growth factor β-1, and high sensitivity C-reactive protein, were unaltered by rifaximin treatment. Rifaximin altered abundance of bacterial taxa in blood marginally, only a decrease in Pseudomonadales was observed. In feces, rifaximin decreased bacterial richness, but effect on particular species was not observed. Subgroup analyses on patients with severely disturbed hemodynamics (n = 34) or activated lipopolysaccharide binding protein (n = 37) revealed no effect of rifaximin.

CONCLUSION

Four weeks of treatment with rifaximin had no impact on the inflammatory state and only minor effects on BT and intestinal bacterial composition in stable, decompensated cirrhosis (NCT01769040).

Mycobacterium tuberculosis strains induce strain-specific cytokine and chemokine response in pulmonary epithelial cells

M. tuberculosis F15/LAM4/KZN has been associated with high transmission rates of drug resistant tuberculosis in the KwaZulu-Natal province of South Africa. The current study elucidated the cytokine/chemokine responses induced by representatives of the F15/LAM4/KZN and other dominant strain families in pulmonary epithelial cells. Multiplex cytokine analyses were performed at 24, 48 and 72h post infection of the A549 pulmonary epithelial cell line with the F15/LAM4/KZN, F28, F11, Beijing, Unique and H37Rv strains at an MOI of ∼10:1. Twenty-three anti- and pro-inflammatory cytokines/chemokines were detected at all-time intervals. Significantly high concentrations of IL-6, IFN-γ, TNF-α and G-CSF at 48h, and IL-8, IFN-γ, TNF-α, G-CSF and GM-CSF at 72h, were induced by the F28 and F15/LAM4/KZN strains, respectively. Lower levels of cytokines/chemokines were induced by either the Beijing or Unique strains at all three time intervals. All strains induced up-regulation of pathogen recognition receptors (PRRs) (TLR3 and TLR5) while only the F15/LAM4/KZN, F11 and F28 strains induced significant differential expression of TLR2 compared to the Beijing, Unique and H37Rv strains. The low induction of cytokines in epithelial cells by the Beijing strain correlates with its previously reported hypervirulent properties. High concentrations of cytokines and chemokines required for early protection against M. tuberculosis infections induced by the F15/LAM4/KZN and F28 strains suggests a lower virulence of these genotypes compared to the Beijing strain. These findings demonstrate the high diversity in host cytokine/chemokine response to early infection of pulmonary epithelial cells by different strains of M. tuberculosis.

Microbiota, cirrhosis, and the emerging oral-gut-liver axis

Cirrhosis is a prevalent cause of morbidity and mortality, especially for those at an advanced decompensated stage. Cirrhosis development and progression involves several important interorgan communications, and recently, the gut microbiome has been implicated in pathophysiology of the disease. Dysbiosis, defined as a pathological change in the microbiome, has a variable effect on the compensated versus decompensated stage of cirrhosis. Adverse microbial changes, both in composition and function, can act at several levels within the gut (stool and mucosal) and have also been described in the blood and oral cavity. While dysbiosis in the oral cavity could be a source of systemic inflammation, current cirrhosis treatment modalities are targeted toward the gut-liver axis and do not address the oral microbiome. As interventions designed to modulate oral dysbiosis may delay progression of cirrhosis, a better understanding of this process is of the utmost importance. The concept of oral microbiota dysbiosis in cirrhosis is relatively new; therefore, this review will highlight the emerging role of the oral-gut-liver axis and introduce perspectives for future research.

Gut Microbiome-based Therapeutics in Liver Cirrhosis: Basic Consideration for the Next Step

Infections account for significant morbidity and mortality in liver cirrhosis and most are related to the gut microbiome. Fecal dysbiosis, characterized by an overgrowth of potentially pathogenic bacteria and a decrease in autochthonous non-pathogenic bacteria, becomes prominent with the progression of liver cirrhosis. In cirrhotic patients, disruption of the intestinal barrier causes intestinal hyperpermeability (i.e. leaky gut), which is closely related to gut dysmotility, dysbiosis and small intestinal bacterial overgrowth and may induce pathological bacterial translocation. Although the involved microbial taxa are somewhat different between the cirrhotic patients from the East and the West, the common manifestation of a shortage of bacteria that contribute to the production of short-chain fatty acids and secondary bile acids may facilitate intestinal inflammation, leaky gut and gut dysbiosis. Translocated endotoxin and bacterial DNA are capable of provoking potent inflammation and affecting the metabolic and hemodynamic systems, which may ultimately enhance the progression of liver cirrhosis and its various complications, such as hepatic encephalopathy (HE), variceal bleeding, infection and renal disturbances. Among studies on the microbiome-based therapeutics, findings of probiotic effects on HE have been contradictory in spite of several supportive results. However, the effects of synbiotics and prebiotics are substantially documented. The background of their effectiveness should be evaluated again in relation to the cirrhosis-related changes in gut microbiome and their metabolic effects. Strict indications for the antibiotic rifaximin remain unestablished, although its effect is promising, improving HE and other complications with little influence on microbial populations. The final goal of microbiome-based therapeutics is to adjust the gut-liver axis to the maximal benefit of cirrhotic patients, with the aid of evolving metagenomic and metabolomic analyses.

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.

Type I interferon signaling in systemic immune cells from patients with alcoholic cirrhosis and its association with outcome

BACKGROUND & AIMS

In immune cells, constitutively and acutely produced type I interferons (IFNs) engage autocrine/paracrine signaling pathways to induce IFN-stimulated genes (ISGs). Enhanced activity of IFN signaling pathways can cause excessive inflammation and tissue damage. We aimed to investigate ISG expression in systemic immune cells from patients with decompensated alcoholic cirrhosis, and its association with outcome.

METHODS

Peripheral blood mononuclear cells (PBMCs) from patients and heathy subjects were stimulated or not with lipopolysaccharide (LPS, an IFN inducer) or increasing concentrations of IFN-β. The expression of 48 ISGs and ten "non-ISG" inflammatory cytokines were analyzed using RT-qPCR.

RESULTS

We developed an 8-ISG signature (IFN score) assessing ISG expression. LPS-stimulated ISG induction was significantly lower in PBMCs from patients with cirrhosis compared to healthy controls. Non-ISGs, however, showed higher induction. Lower induction of ISGs by LPS was not due to decreased IFN production by cirrhotic PBMCs or neutralization of secreted IFN, but a defective PBMC response to IFN. This defect was at least in part due to decreased constitutive ISG expression. Patients with the higher baseline IFN scores and ISG levels had the higher risk of death. At baseline, "non-ISG" cytokines did not correlate with outcome.

CONCLUSIONS

PBMCs from patients with decompensated alcoholic cirrhosis exhibit downregulated ISG expression, both constitutively and after an acute stimulus. Our finding that higher baseline PBMC ISG expression was associated with higher risk of death, suggests that constitutive ISG expression in systemic immune cells contributes to the prognosis of alcoholic cirrhosis.

LAY SUMMARY

Enhanced activity of IFN signaling pathways can cause excessive inflammation and tissue damage. Here we show that peripheral blood mononuclear cells (PBMCs) from patients with alcoholic cirrhosis exhibit a defect in interferon-stimulated genes (ISGs). We found that higher baseline ISG expression in PBMCs was associated with higher risk of death, revealing a probable contribution of ISG expression in immune cells to the outcome of alcoholic cirrhosis.

Dysfunction of Circulating Polymorphonuclear Leukocytes and Monocytes in Ambulatory Cirrhotics Predicts Patient Outcome

BACKGROUND

Cirrhosis represents a state of functional immune paresis with increased infection risk.

AIMS

To investigate polymorphonuclear (PMN) leukocyte and monocyte function in ambulatory cirrhotics, and their potential relation with cirrhosis etiology or patient outcome.

METHODS

Consecutive ambulatory cirrhotics without current or recent (<1 month) infection or acute decompensation were prospectively enrolled in 2013 and followed for a median time of 20 months until death, transplant or end of 2014. Oxidative burst and phagocytosis of circulating PMNs and monocytes were investigated at baseline and after in vitro Escherichia coli stimulation. Seventeen healthy blood donors served as controls. Baseline clinical and laboratory data as well as follow-up data on the development of cirrhosis complications, including acute-on-chronic liver failure (ACLF), and bacterial infections were collected.

RESULTS

Sixty patients were included (70 % male, median age 63 years, 52 % with alcoholic cirrhosis). Compared to controls, cirrhotics showed increased resting and stimulated burst as well as reduced phagocytosis of PMNs, and increased stimulated monocyte burst (p < 0.05 for all). Alcoholic etiology was not related to PMN or monocyte dysfunction (p > 0.05 for all). In Cox regression analysis, increased stimulated monocyte and PMN burst were independent predictors of sepsis, severe sepsis and ACLF occurrence. Also, increased stimulated monocyte burst was associated with worse transplant-free survival (p < 0.05 for all).

CONCLUSIONS

Stimulated PMN and monocyte oxidative burst are increased in ambulatory cirrhotics without acute decompensation. In turn, these changes are associated to sepsis and ACLF occurrence.

Interaction between periodontitis and liver diseases

Periodontitis is an oral disease that is highly prevalent worldwide, with a prevalence of 30–50% of the population in developed countries, but only ~10% present with severe forms. It is also estimated that periodontitis results in worldwide productivity losses amounting to ~54 billion USD yearly. In addition to the damage it causes to oral health, periodontitis also affects other types of disease. Numerous studies have confirmed the association between periodontitis and systemic diseases, such as diabetes, respiratory disease, osteoporosis and cardiovascular disease. Increasing evidence also indicated that periodontitis may participate in the progression of liver diseases, such as non-alcoholic fatty liver disease, cirrhosis and hepatocellular carcinoma, as well as affecting liver transplantation. However, to the best of our knowledge, there are currently no reviews elaborating upon the possible links between periodontitis and liver diseases. Therefore, the current review summarizes the human trials and animal experiments that have been conducted to investigate the correlation between periodontitis and liver diseases. Furthermore, in the present review, certain mechanisms that have been postulated to be responsible for the role of periodontitis in liver diseases (such as bacteria, pro-inflammatory mediators and oxidative stress) are considered. The aim of the review is to introduce the hypothesis that periodontitis may be important in the progression of liver disease, thus providing dentists and physicians with an improved understanding of this issue.

Curcumin alleviates lipopolysaccharide induced sepsis and liver failure by suppression of oxidative stress-related inflammation via PI3K/AKT and NF-κB related signaling

In many liver disorders, oxidative stress-related inflammation and apoptosis are important pathogenic components, finally resulting in acute liver failure. Erythropoietin and its analogues are well known to influence the interaction between apoptosis and inflammation in brain and kidney. The study is to clarify the effect of curcumin, a natural plant phenolic food additive, on lipopolysaccharides (LPS)-induced acute liver injury of mice with endotoxemia and associated molecular mechanism from inflammation, apoptosis and oxidative stress levels. And curcumin, lowered serum cytokines, including Interleukin 1beta (IL-1β), Interleukin 6 (IL-6) and tumor necrosis factor (TNF-α), and improved liver apoptosis through suppressing phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway and inhibiting Cyclic AMP-responsive element-binding protein (CREB)/Caspase expression, and decreased oxidative stress-associated protein expression, mainly involving 2E1 isoform of cytochrome P450/nuclear factor E2-related factor 2/reactive oxygen species (CYP2E/Nrf2/ROS) signaling pathway, as well as liver nitric oxide (NO) production in LPS-induced mice. Moreover, curcumin regulated serum alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP), accelerated liver antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GSH-px) levels, and inhibited activation of the mitogen-activated protein kinases/c-Jun NH2-terminal kinase (P38/JNK) cascade in the livers of LPS-induced rats. Thus, curcumin treatment attenuates LPS-induced PI3K/AKT and CYP2E/Nrf2/ROS signaling and liver injury. Strategies to inhibit inflammation and apoptosis signaling may provide alternatives to the current clinical approaches to improve oxidative responses of endotoxemia.

Toll-like receptors in the pathogenesis of pulmonary fibrosis

Pulmonary fibrosis (PF) constitutes the end stage of a broad range of heterogeneous interstitial lung diseases, characterized by the destruction of the pulmonary parenchyma, deposition of extracellular matrix and dramatic changes in the phenotype of both fibroblasts and alveolar epithelial cells. More than 200 causes of pulmonary fibrosis have been identified so far, yet the most common form is idiopathic pulmonary fibrosis (IPF). IPF is a lethal lung disorder of unknown etiology with a gradually increasing worldwide incidence and a median survival of 3-5 years from the time of diagnosis. Despite intense research efforts, the pathogenesis remains elusive and no effective treatment is available. Accumulating body of evidence suggests an abnormal wound healing response followed by extracellular matrix deposition, destruction of lung architecture, ultimately leading to respiratory failure. The contribution of immune system in lung fibrogenesis had been largely underscored due to the absence of response to immunosuppressive agents; however, the premise that lung fibrosis has an immunologic background has been recently revived. Toll-like receptors (TLRs) are pattern recognition receptors (PRRs), which link innate and adaptive immune response and regulate wound healing. TLRs promote tissue repair or fibrosis in many disease settings including lung fibrosis, albeit with profound differences depending on the cellular microenvironment. This review summarizes the current state of knowledge regarding the mechanistic implications between TLRs and lung fibrosis and highlights the therapeutic potential of targeting TLR signaling at the ligand or receptor level.

Acute-on-chronic liver failure in cirrhosis

The definition of acute-on-chronic liver failure (ACLF) remains contested. In Europe and North America, the term is generally applied according to the European Association for the Study of the Liver-Chronic Liver Failure (EASL-CLIF) Consortium guidelines, which defines this condition as a syndrome that develops in patients with cirrhosis and is characterized by acute decompensation, organ failure and high short-term mortality. One-third of patients who are hospitalized for acute decompensation present with ACLF at admission or develop the syndrome during hospitalization. ACLF frequently occurs in a closed temporal relationship to a precipitating event, such as bacterial infection or acute alcoholic, drug-induced or viral hepatitis. However, no precipitating event can be identified in approximately 40% of patients. The mechanisms of ACLF involve systemic inflammation due to infections, acute liver damage and, in cases without precipitating events, probably intestinal translocation of bacteria or bacterial products. ACLF is graded into three stages (ACLF grades 1-3) on the basis of the number of organ failures, with higher grades associated with increased mortality. Liver and renal failures are the most common organ failures, followed by coagulation, brain, circulatory and respiratory failure. The 28-day mortality rate associated with ACLF is 30%. Depending on the grade, ACLF can be reversed using standard therapy in only 16-51% of patients, leaving a considerable proportion of patients with ACLF that remains steady or progresses. Liver transplantation in selected patients with ACLF grade 2 and ACLF grade 3 increases the 6-month survival from 10% to 80%.

Impaired intracellular signaling, myeloperoxidase release and bactericidal activity of neutrophils from patients with alcoholic cirrhosis

BACKGROUND & AIMS

Myeloperoxidase exocytosis and production of hydrogen peroxide via the neutrophil superoxide-generating nicotinamide adenine dinucleotide phosphate (NADPH) oxidase contribute to efficient elimination of bacteria. Cirrhosis impairs immune functions and increases susceptibility to bacterial infection. We recently showed that neutrophils from patients with decompensated alcoholic cirrhosis exhibit a severe impairment of formylpeptide receptor (fPR)-mediated intracellular signaling and superoxide production. Here, we performed ex vivo studies with these patients' neutrophils to further investigate myeloperoxidase release, bactericidal capacity and signaling events following fPR stimulation by the formylpeptide formyl-met-leu-phe (fMLP).

METHODS

Myeloperoxidase release was studied by measuring extracellular myeloperoxidase activity. Activation of signaling effectors was studied by Western blot and their respective contribution to myeloperoxidase release studied using pharmacological antagonists.

RESULTS

fMLP-induced myeloperoxidase release was strongly impaired in patients' neutrophils whereas the intracellular myeloperoxidase stock was unaltered. The fMLP-induced phosphorylation of major signaling effectors, AKT, ERK1/2 and p38-MAP-Kinases, was also strongly deficient despite a similar expression of signaling effectors or fPR. However, based on effector inhibition in healthy neutrophils, AKT and p38-MAPK but not ERK1/2 upregulated fMLP-induced myeloperoxidase exocytosis. Interestingly, patients' neutrophils exhibited a defective bactericidal capacity that was reversed ex vivo by the TLR7/8 agonist CL097, through potentiation of the fMLP-induced AKT/p38-MAPK signaling axis and myeloperoxidase release.

CONCLUSIONS

We provide first evidence that neutrophils from patients with decompensated alcoholic cirrhosis exhibit a deficient AKT/p38-MAPK signaling, myeloperoxidase release and bactericidal activity, which can be reversed via TLR7/8 activation. These defects, together with the previously described severe deficient superoxide production, may increase cirrhotic patients' susceptibility to bacterial infections.

Role of Infections in Acute-on-Chronic Liver Failure

Patients with cirrhosis are prone to developing bacterial infections. Moreover, bacterial infection is the most common identifiable trigger of acute-on-chronic liver failure (ACLF), which is characterized by organ failures and a high risk of death. There is evidence of an excessive immune response of the host as a major mechanism leading to the development of organ failures in patients with cirrhosis. However, a role for direct tissue damage caused by bacterial toxins and virulence factors cannot be excluded. Failed tolerance mechanisms may also contribute to organ failures, although the involved mechanisms are unclear. A proportion of patients with infection-related ACLF have a prolonged stay in the intensive care unit. These patients have immune suppression, increased risk of superinfection and poor outcome. Immune suppression might be a consequence of the first infection episode that has led patients to be admitted to hospital.

Decreased Tim-3 expression is associated with functional abnormalities of monocytes in decompensated cirrhosis without overt bacterial infection

BACKGROUND & AIMS

Patients with advanced cirrhosis usually exhibit altered monocyte function. However, the molecular mechanisms underlying the functional changes of monocytes are poorly understood.

METHODS

We investigated the role of T-cell immunoglobulin domain and mucin domain-containing molecule-3 (Tim-3) in regulating monocyte function in 94 patients with decompensated liver cirrhosis (DC-LC) (decompensation was defined by ascites, hepatic encephalopathy or upper gastrointestinal bleeding), 58 with compensated liver cirrhosis (C-LC) and 52 healthy controls (HC) by characterizing the frequency of Tim-3(+) monocytes, their phagocytosis capacity, HLA-DR expression, cytokine secretion and MAP kinase activation induced by lipopolysaccharide (LPS).

RESULTS

Tim-3 expression on CD14(+) monocytes in DC-LC group were significantly lower than that in C-LC and HC and were associated with increased levels of plasma endotoxin, enhanced cytokine production, decreased phagocytic capacity, and reduced HLA-DR expression. Tim-3 expression on monocytes and monocyte function did not differ between C-LC and HC group. Tim-3(+)CD14(+) cells had more potent phagocytic capacity, higher levels of HLA-DR, CD86, CD80, CD163, and CD206 expression, but lower levels of CD1a and CD83, related to that of Tim-3(-)CD14(+) monocytes. In addition, Tim-3(+)CD14(+) cells produced less TNF-α but higher levels of IL-10 in response to LPS. Treatment with anti-Tim-3 antibody significantly reduced phagocytic capacity, but enhanced LPS-stimulated TNF-α, IL-6, and IL-10 secretion. Furthermore, blocking Tim-3 signaling increased p38 MAP kinase phosphorylation in monocytes upon LPS stimulation.

CONCLUSIONS

Downregulation of Tim-3 expression was associated with endotoxemia and functional alterations of monocytes in patients with decompensated cirrhosis.

Acute-on-chronic liver failure: A new syndrome that will re-classify cirrhosis

Acute-on-chronic liver failure (ACLF) is a recently recognized syndrome characterized by acute decompensation (AD) of cirrhosis and organ/system failure(s) (organ failure: liver, kidney, brain, coagulation, circulation and/or respiration) and extremely poor survival (28-day mortality rate 30-40%). ACLF occurs in relatively young patients. It is especially frequent in alcoholic- and untreated hepatitis B associated-cirrhosis, in addition it is related to bacterial infections and active alcoholism, although in 40% of cases no precipitating event can be identified. It may develop at any time during the course of the disease in the patient (from compensated to long-standing cirrhosis). The development of ACLF occurs in the setting of a systemic inflammation, the severity of which correlates with the number of organ failures and mortality. Systemic inflammation may cause ACLF through complex mechanisms including an exaggerated inflammatory response and systemic oxidative stress to pathogen- or danger/damage-associated molecular patterns (immunopathology) and/or alteration of tissue homeostasis to inflammation caused either by the pathogen itself or through a dysfunction of tissue tolerance. A scoring system composed of three scores (CLIF-C OFs, CLIF-C AD, and CLIF-C ACLFs) specifically designed for patients with AD, with and without ACLF, allows a step-wise algorithm for a rational indication of therapy. The management of ACLF should be carried out in enhanced or intensive care units. Current therapeutic measures comprise the treatment for associated complications, organ failures support and liver transplantation.

Chronic alcohol exposure exacerbates inflammation and triggers pancreatic acinar-to-ductal metaplasia through PI3K/Akt/IKK

Pancreatic acinar-to-ductal metaplasia (ADM) has been identified as an initiating event that can progress to pancreatic intraepithelial neoplasia (PanIN) or pancreatic ductal adenocarcinoma (PDAC). Acini transdifferentiation can be induced by persistent inflammation. Notably, compelling evidence has emerged that chronic alcohol exposure may trigger an inflammatory response of macrophages/monocytes stimulated by endotoxins. In the present study, we aimed to evaluate the role of inflammation induced by chronic alcohol and lipopolysaccharide (LPS) exposure in the progression of pancreatic ADM, as well as to elucidate the possible mechanisms involved. For this purpose, cultured macrophages were exposed to varying doses of alcohol for 1 week prior to stimulation with LPS. Tumor necrosis factor-α (TNF-α) and regulated upon activation, normal T cell expression and secreted (RANTES) expression were upregulated in the intoxicated macrophages with activated nuclear factor-κB (NF-κB). Following treatment with the supernatant of intoxicated macrophages, ADM of primary acinar cells was induced. Furthermore, the expression of TNF-α and RANTES, as well as the phosphatidylinositol-3-kinase (PI3K)/protein kinase B(Akt)/inhibitory κB kinase (IKK) signaling pathway have been proven to be involved in the ADM of acinar cells. Moreover, Sprague-Dawley (SD) rats were employed to further explore the induction of pancreatic ADM by chronic alcohol and LPS exposure in vivo. At the end of the treatment period, a number of physiological parameters, such as body weight, liver weight and pancreatic weight were reduced in the exposed rats. Plasma alcohol concentrations and oxidative stress levels in the serum, as well as TNF-α and RANTES expression in monocytes were also induced following chronic alcohol and LPS exposure. In addition, pancreatic ADM was induced through the PI3K/Akt/IKK signaling pathway by the augmented TNF-α and RANTES expression levels in the exposed rats. Overall, we characterized the link between inflammation induced by chronic alcohol and LPS exposure and pancreatic ADM. However, the mechanisms behind the induction of pancreatic ADM warrant further investigation.

Cirrhosis-associated immune dysfunction: distinctive features and clinical relevance

The term cirrhosis-associated immune dysfunction refers to the main syndromic abnormalities of immune function, immunodeficiency and systemic inflammation that are present in cirrhosis. The course of advanced cirrhosis, regardless of its aetiology, is complicated by cirrhosis-associated immune dysfunction and this constitutes the pathophysiological hallmark of an increased susceptibility to bacterial infection, distinctive of the disease. Cirrhosis impairs the homeostatic role of the liver in the systemic immune response. Damage to the reticulo-endothelial system compromises the immune surveillance function of the organ and the reduced hepatic synthesis of proteins, involved in innate immunity and pattern recognition, hinders the bactericidal ability of phagocytic cells. Systemic inflammation, in form of activated circulating immune cells and increased serum levels of pro-inflammatory cytokines, is the result of persistent episodic activation of circulating immune cells from damage-associated molecular patterns, released from necrotic liver cells and, as cirrhosis progresses, from pathogen-associated molecular patterns, released from the leaky gut. Cirrhosis-associated immune dysfunction phenotypes switch from predominantly "pro-inflammatory" to predominantly "immunodeficient" in patients with stable ascitic cirrhosis and in patients with severely decompensated cirrhosis and extra-hepatic organ failure (e.g. acute-on-chronic liver failure), respectively. These cirrhosis-associated immune dysfunction phenotypes represent the extremes of a spectrum of reversible dynamic events that take place during the course of cirrhosis. Systemic inflammation can affect the functions of tissue somatic cells and modify the clinical manifestation of cirrhosis. The best characterized example is the contribution of systemic inflammation to the haemodynamic derangement of cirrhosis, which correlates negatively with prognosis.

Post-paracentesis circulatory derangements are related to monocyte activation

BACKGROUND & AIMS

Post-paracentesis circulatory dysfunction is associated with development of hepatorenal syndrome and increased mortality. The impact of large volume paracentesis (LVP) on the 24-h blood pressure (BP) profile is unknown, and the relationship to Na+-retentive and pro-inflammatory cytokines also remains unknown. The aims of this study were to (i) define the effects of LVP with albumin administration on 24-h BP profiles, and (ii) relate changes in BP over time to changes in Na+-retentive hormones, clinical factors and inflammatory cytokines.

METHODS

Ten patients undergoing LVP had 24-h ambulatory BP monitoring performed pre- and post-paracentesis. Markers of the innate immune system, bacterial translocation and Na+-retentive hormones were drawn pre- and post-LVP.

RESULTS

Mean arterial pressure (MAP) dropped in nine of the 10 patients in the 24 h following a paracentesis compared to 24 h preceding the procedure (mean drop of 5.5 mmHg, P<0.005). A mixed effects model was used to define time-covariate interactions in predicting changes in BP profile. Monocyte chemotactic protein-1 (MCP1) was associated with Δsystolic BP (β=-0.011, P<0.05), Δdiastolic BP (β=-0.012, P<0.05) and ΔMAP (β=-0.012, P<0.05). Plasma renin activity was also significantly associated with Δsystolic BP (β=-0.21, P<0.05). Renal function was also significantly reduced following LVP.

CONCLUSIONS

Systolic, diastolic and MAP decreased over 24 h after LVP compared to the 24 h pre-LVP. This drop is related to increases in MCP-1 after LVP. Increased MCP-1, a marker of monocyte activation, was strongly related to changes in BP.

IRAK-M deficiency promotes the development of type 1 diabetes in NOD mice

Type 1 diabetes mellitus (T1DM) is an organ-specific autoimmune disease characterized by progressive destruction of insulin-secreting pancreatic β-cells. Both T-cell-mediated adaptive responses as well as innate immune processes are involved in pathogenesis. Interleukin-1 receptor-associated kinase M (IRAK-M) can effectively inhibit the MyD88 downstream signals in Toll-like receptor pathways, while lack of IRAK-M is known to be associated with autoimmunity. Our study showed that IRAK-M-deficient (IRAK-M(-/-)) nonobese diabetic (NOD) mice displayed early onset and rapid progression of T1DM with impaired glucose tolerance, more severe insulitis, and increased serum anti-insulin autoantibodies. Mechanistic studies showed that the enhanced activation and antigen-presenting function of IRAK-M(-/-) antigen-presenting cells from IRAK-M(-/-) mice were responsible for the rapid progression of disease. Moreover, IRAK-M(-/-) dendritic cells induced enhanced activation of diabetogenic T cells in vitro and the rapid onset of T1DM in vivo in immunodeficient NOD mice when cotransferred with diabetogenic T cells. This study illustrates how the modulation of innate immune pathways through IRAK-M influences the development of autoimmune diabetes.

Bacterial infections in cirrhosis: a position statement based on the EASL Special Conference 2013

Bacterial infections are very common and represent one of the most important reasons of progression of liver failure, development of liver-related complications, and mortality in patients with cirrhosis. In fact, bacterial infections may be a triggering factor for the occurrence of gastrointestinal bleeding, hypervolemic hyponatremia, hepatic encephalopathy, kidney failure, and development of acute-on-chronic liver failure. Moreover, infections are a very common cause of repeated hospitalizations, impaired health-related quality of life, and increased healthcare costs in cirrhosis. Bacterial infections develop as a consequence of immune dysfunction that occurs progressively during the course of cirrhosis. In a significant proportion of patients, infections are caused by gram-negative bacteria from intestinal origin, yet gram-positive bacteria are a frequent cause of infection, particularly in hospitalized patients. In recent years, infections caused by multidrug-resistant bacteria are becoming an important clinical problem in many countries. The reduction of the negative clinical impact of infections in patients with cirrhosis may be achieved by a combination of prophylactic measures, such as administration of antibiotics, to reduce the occurrence of infections in high-risk groups together with early identification and management of infection once it has developed. Investigation on the mechanisms of altered gut microflora, translocation of bacteria, and immune dysfunction may help develop more effective and safe methods of prevention compared to those that are currently available. Moreover, research on biomarkers of early infection may be useful in early diagnosis and treatment of infections. The current manuscript reports an in-depth review and a position statement on bacterial infections in cirrhosis.

Gene- and exon-expression profiling reveals an extensive LPS-induced response in immune cells in patients with cirrhosis

BACKGROUND & AIMS

Lipopolysaccharide (LPS)-expressing bacteria cause severe inflammation in cirrhotic patients. The global gene response to LPS is unknown in cirrhotic immune cells.

METHODS

Gene-expression profiling using Affymetrix Human Exon Array analyzed the expression of 14,851 genes in LPS-stimulated peripheral blood mononuclear cells (PBMCs) from 4 patients with cirrhosis and 4 healthy subjects. We performed validation studies using RT-qPCR in LPS-stimulated PBMCs from 52 patients and 9 healthy subjects and investigated the association of gene induction with mortality in 26 patients.

RESULTS

Gene-expression profiling of LPS-stimulated cirrhotic cells showed 509 upregulated genes and 1588 downregulated genes. In LPS-stimulated "healthy" cells, 952 genes were upregulated and 838 genes downregulated. The 741 LPS-regulated genes shared by cirrhotic and "healthy" cells were involved in cytokine production/activity and induction of "immune paralysis". Comparison of functions associated with the 1356 genes, specifically regulated by LPS in cirrhotic cells, to functions of the 1049 genes, specifically regulated in "healthy" cells, allowed to define a cirrhosis-specific phenotype. Unlike in "healthy" cells, LPS failed to induce an interferon-mediated program in cirrhotic cells. In cirrhotic PBMCs, LPS specifically induced certain molecules involved in apoptosis and downregulated molecules involved in endocytic trafficking. RT-qPCR experiments showed that LPS-stimulated cirrhotic PBMCs had an enhanced induction of certain proinflammatory cytokines and chemokines. In the prognosis study, higher ex vivo LPS-induction of the inflammatory genes IL6 and CXCL5 was a significant predictor of mortality.

CONCLUSIONS

Our results show that LPS-stimulated cirrhotic PBMCs exhibit an extensive and often unexpected transcriptional response.

Mitochondrial DNA maintenance is regulated in human hepatoma cells by glycogen synthase kinase 3β and p53 in response to tumor necrosis factor α

During chronic liver inflammation, up-regulated Tumor Necrosis Factor alpha (TNF-α) targets hepatocytes and induces abnormal reactive oxygen species (ROS) production responsible for mitochondrial DNA (mtDNA) alterations. The serine/threonine Glycogen Synthase Kinase 3 beta (GSK3β) plays a pivotal role during inflammation but its involvement in the maintenance of mtDNA remains unknown. The aim of this study was to investigate its involvement in TNF-α induced mtDNA depletion and its interrelationship with p53 a protein known to maintain mtDNA copy numbers. Using quantitative polymerase chain reaction (qPCR) we found that at 30 min in human hepatoma HepG2 cells TNF-α induced 0.55±0.10 mtDNA lesions per 10 Kb and a 52.4±2.8% decrease in mtDNA content dependent on TNF-R1 receptor and ROS production. Both lesions and depletion returned to baseline from 1 to 6 h after TNF-α exposure. Luminol-amplified chemiluminescence (LAC) was used to measure the rapid (10 min) and transient TNF-α induced increase in ROS production (168±15%). A transient 8-oxo-dG level of 1.4±0.3 ng/mg DNA and repair of abasic sites were also measured by ELISA assays. Translocation of p53 to mitochondria was observed by Western Blot and co-immunoprecipitations showed that TNF-α induced p53 binding to GSK3β and mitochondrial transcription factor A (TFAM). In addition, mitochondrial D-loop immunoprecipitation (mtDIP) revealed that TNF-α induced p53 binding to the regulatory D-loop region of mtDNA. The knockdown of p53 by siRNAs, inhibition by the phosphoSer(15)p53 antibody or transfection of human mutant active GSK3βS9A pcDNA3 plasmid inhibited recovery of mtDNA content while blockade of GSK3β activity by SB216763 inhibitor or knockdown by siRNAs suppressed mtDNA depletion. This study is the first to report the involvement of GSK3β in TNF-α induced mtDNA depletion. We suggest that p53 binding to GSK3β, TFAM and D-loop could induce recovery of mtDNA content through mtDNA repair.

Abnormal plasma microparticles impair vasoconstrictor responses in patients with cirrhosis

BACKGROUND & AIMS

Circulating membrane-shed microparticles (MPs) participate in regulation of vascular tone. We investigated the cellular origins of MPs in plasma from patients with cirrhosis and assessed the contribution of MPs to arterial vasodilation, a mechanism that contributes to portal hypertension.

METHODS

We analyzed MPs from blood samples of 91 patients with cirrhosis and 30 healthy individuals (controls) using flow cytometry; their effects on the vascular response to vasoconstrictors were examined in vitro and in vivo.

RESULTS

Circulating levels of leuko-endothelial (CD31(+)/41(-)), pan-leukocyte (CD11a(+)), lymphocyte (CD4(+)), and erythrocyte (CD235a(+)) MPs were higher in patients with cirrhosis than in controls. Plasma of patients with cirrhosis contained hepatocyte-derived MPs (cytokeratin-18(+)), whereas plasma from controls did not. The severity of cirrhosis and systemic inflammation were major determinants of the levels of leuko-endothelial and hepatocyte MPs. MPs from patients with advanced cirrhosis significantly impaired contraction of vessels in response to phenylephrine, whereas MPs from healthy controls or from patients of Child-Pugh class A did not. This effect depended on cyclooxygenase type 1 and required phosphatidylserine on the surface of MPs. Intravenous injection of MPs from patients with cirrhosis into BALB/C mice decreased mean arterial blood pressure.

CONCLUSIONS

Cirrhosis is associated with increases in circulating subpopulations of MPs, likely resulting from systemic inflammation and liver cell damage. The overall pool of circulating MPs from patients with advanced cirrhosis impairs vasoconstrictor responses and decreases blood pressure, contributing to the arterial vasodilation associated with portal hypertension.

Management of bacterial infections in cirrhosis

Bacterial infections are very frequent in advanced cirrhosis and become the first cause of death of these patients. Despite numerous experimental data and significant advances in the understanding of the pathogenesis of sepsis in cirrhosis, the outcome remains poor. Classical diagnostic parameters such as C-reactive protein and SIRS criteria have less diagnostic capacity in the cirrhotic population, often delaying the diagnosis and the management of bacterial infection. Prompt and appropriate empirical antibiotic treatment of infection and early resuscitation of patients with severe sepsis or septic shock are essential in determining patient's outcome. A strategy of careful restriction of prophylactic antibiotics to the high-risk populations could reduce the spread of multidrug resistant bacteria. This review is focused on the currently recommended diagnostic, therapeutic and prophylactic strategies for bacterial infections in the cirrhotic population.

Toll-like receptors in liver fibrosis: cellular crosstalk and mechanisms

Toll-like receptors (TLRs) are pattern recognition receptors that distinguish conserved microbial products, also known as pathogen-associated molecular patterns (PAMPs), from host molecules. Liver is the first filter organ between the gastrointestinal tracts and the rest of the body through portal circulation. Thus, the liver is a major organ that must deal with PAMPs and microorganisms translocated from the intestine and to respond to the damage associated molecular patterns (DAMPs) released from injured organs. These PAMPs and DAMPs preferentially activate TLR signaling on various cell types in the liver inducing the production of inflammatory and fibrogenic cytokines that initiate and prolong liver inflammation, thereby leading to fibrosis. We summarize recent findings on the role of TLRs, ligands, and intracellular signaling in the pathophysiology of liver fibrosis due to different etiology, as well as to highlight the potential role of TLR signaling in liver fibrosis associated with hepatitis C infection, non-alcoholic and alcoholic steatoheoatitis, primary biliary cirrhosis, and cystic fibrosis.

Toll-like receptors in secondary obstructive cholangiopathy

Secondary obstructive cholangiopathy is characterized by intra- or extrahepatic bile tract obstruction. Liver inflammation and structural alterations develop due to progressive bile stagnation. Most frequent etiologies are biliary atresia in children, and hepatolithiasis, postcholecystectomy bile duct injury, and biliary primary cirrhosis in adults, which causes chronic biliary cholangitis. Bile ectasia predisposes to multiple pathogens: viral infections in biliary atresia; Gram-positive and/or Gram-negative bacteria cholangitis found in hepatolithiasis and postcholecystectomy bile duct injury. Transmembrane toll-like receptors (TLRs) are activated by virus, bacteria, fungi, and parasite stimuli. Even though TLR-2 and TLR-4 are the most studied receptors related to liver infectious diseases, other TLRs play an important role in response to microorganism damage. Acquired immune response is not vertically transmitted and reflects the infectious diseases history of individuals; in contrast, innate immunity is based on antigen recognition by specific receptors designated as pattern recognition receptors and is transmitted vertically through the germ cells. Understanding the mechanisms for bile duct inflammation is essential for the future development of therapeutic alternatives in order to avoid immune-mediated destruction on secondary obstructive cholangiopathy. The role of TLRs in biliary atresia, hepatolithiasis, bile duct injury, and primary biliary cirrhosis is described in this paper.

Bench-to-beside review: acute-on-chronic liver failure - linking the gut, liver and systemic circulation

The concept of acute-on-chronic liver failure (ACLF) was introduced recently to describe a subset of patients with chronic liver disease presenting with profound deterioration of liver function and rapidly evolving multi-organ failure. ACLF is frequently accompanied by the development of severe inflammatory response syndrome and has a high mortality. To date, treatment options are limited and exclusively supportive. Over the last few years, some insights have been generated in the pathophysiology of ACLF. A key role for the interaction of innate immune dysfunction, enhanced bacterial translocation from the gut, and circulatory dysfunction has been proposed. In this respect, therapeutic strategies have been examined, with variable success, in experimental studies in animals and humans. This review focuses on potentially relevant pathophysiological elements in the development of ACLF and points out promising treatment modalities in ACLF.