Rifaximin and lubiprostone mitigate liver fibrosis development by repairing gut barrier function in diet-induced rat steatohepatitis

BACKGROUND

Although gut-derived lipopolysaccharide (LPS) affects the progression of non-alcoholic steatohepatitis (NASH) pathogenesis, few studies have focused on this relationship to develop treatments for NASH.

AIMS

To explore the effects of combination with rifaximin and lubiprostone on NASH liver fibrosis through the modulation of gut barrier function.

METHODS

To induce steatohepatitis, F344 rats were fed a choline-deficient l-amino acid-defined (CDAA) diet for 12 weeks and received oral administration of rifaximin and/or lubiprostone. Histological, molecular, and fecal microbial analyses were performed. Barrier function in Caco-2 cells were assessed by in vitro assays.

RESULTS

Combination rifaximin/lubiprostone treatment significantly suppressed macrophage expansion, proinflammatory responses, and liver fibrosis in CDAA-fed rats by blocking hepatic translocation of LPS and activation of toll-like receptor 4 signaling. Rifaximin and lubiprostone improved intestinal permeability via restoring tight junction proteins (TJPs) with the intestinal activation of pregnane X receptor and chloride channel-2, respectively. Moreover, this combination increased the abundance of Bacteroides, Lactobacillus, and Faecalibacterium as well as decreased that of Veillonella resulting in an increase of fecal short-chain fatty acids and a decrease of intestinal sialidase activity. Both agents also directly suppressed the LPS-induced barrier dysfunction and depletion of TJPs in Caco-2 cells.

CONCLUSION

The combination of rifaximin and lubiprostone may provide a novel strategy for treating NASH-related fibrosis.

Macrophage Activation Markers Predict Liver-Related Complications in Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) has a wide variation in clinical presentation and course. There is no significant correlation between these symptoms and the disease stage, although patients with more advanced stages generally have more symptoms. It is important to develop biomarkers in order to identify patients with an increased risk of complications and end-stage liver disease. This study investigated surrogate markers for risk estimation of PBC-related complications, including a study population of 77 patients with PBC who underwent liver biopsy and were measured for serum levels of macrophage activation markers, soluble CD163 (sCD163), soluble mannose receptor (sMR), and zonulin. Patients with PBC were divided into symptomatic (Group S, n = 20) and asymptomatic (Group A, n = 57) groups. The correlations of histological stages based on both Scheuer and Nakanuma classifications with the three serum markers were investigated. The Nakanuma classification involves grading for liver fibrosis and bile duct loss. The three biomarkers were assessed for their diagnostic ability to identify patients with PBC having high risk of developing complications. The predictive factors of these complications were examined as well. Group S had significantly higher serum sMR (p = 0.011) and sCD163 (p = 0.048) levels versus Group A. A composite index of sMR and sCD163 measurements had significantly better prediction performance than sCD163 alone (p = 0.012), although not when compared to sMR alone (p = 0.129). Serum sMR was an independent factor for developing complications on both univariate (Odds ratio (OR) = 30.20, 95% confidence interval (95% CI): 3.410−267.0, p = 0.00220), and multivariate (OR = 33.70, 95% CI: 3.6600−311.0, p = 0.0019) analyses. Patients with PBC having sMR of ≥56.6 had a higher incidence of clinical complications versus those with a sMR of <56.6. Serum sMR predicts the development of complications in patients with PBC. sMR plus sCD163 showed better predictive power than either marker alone, although the addition of sCD163 did not improve the predictive power of sMR. Future prospective studies are required in order to validate the findings of the present study.

Rifaximin enhances the L‑carnitine‑mediated preventive effects on skeletal muscle atrophy in cirrhotic rats by modulating the gut‑liver‑muscle axis

The gut‑liver‑muscle axis is associated with the development of sarcopenia in liver cirrhosis. The present study aimed to illustrate the combined effects of rifaximin and L‑carnitine on skeletal muscle atrophy in cirrhotic rats with steatohepatitis. For this purpose, a total of 344 Fischer rats were fed a choline‑deficient L‑amino acid‑defined (CDAA) diet with the daily oral administration of rifaximin (100 mg/kg) and/or L‑carnitine (200 mg/kg), and measurements of psoas muscle mass index and forelimb grip strength were performed. After feeding for 12 weeks, blood samples, and liver, ileum and gastrocnemius muscle tissues were harvested. The effects of L‑carnitine on rat myocytes were assessed using in vitro assays. Treatment with rifaximin attenuated hyperammonemia and liver fibrosis in the CDAA‑fed rats. Moreover, it improved intestinal permeability with the restoration of tight junction proteins and suppressed the lipopolysaccharide (LPS)‑mediated hepatic macrophage activation and pro‑inflammatory response. In addition, rifaximin prevented skeletal muscle mass atrophy and weakness by decreasing intramuscular myostatin and pro‑inflammatory cytokine levels. Moreover, rifaximin synergistically enhanced the L‑carnitine‑mediated improvement of skeletal muscle wasting by promoting the production of insulin‑like growth factor‑1 and mitochondrial biogenesis, resulting in the inhibition of the ubiquitin‑proteasome system (UPS). The in vitro assays revealed that L‑carnitine directly attenuated the impairment of mitochondrial biogenesis, thereby inhibiting the UPS in rat myocytes that were stimulated with LPS or tumor necrosis factor‑α. On the whole, the present study demonstrates that the combination of rifaximin with L‑carnitine may provide a clinical benefit for liver cirrhosis‑related sarcopenia.

Endotoxin Activity Reflects an Increase in Body Temperature in Cirrhotic Patients With Ascites Undergoing Cell-free and Concentrated Ascites Reinfusion Therapy

BACKGROUND

Ascites commonly complicates cirrhosis and is refractory to the vasopressin-2 antagonist tolvaptan and fluid restriction in approximately 60% of patients. We aimed to identify risk factors associated with adverse events following cell-free and concentrated ascites reinfusion therapy (CART) in patients with cirrhosis and ascites.

PATIENTS AND METHODS

We evaluated the efficacy and tolerability to the CART system in 18 patients with decompensated liver cirrhosis and ascites. We determined serum endotoxin activity using endotoxin activity (EA) assays and serum and ascitic fluid concentrations of interleukin 6 (IL6) and tumor necrosis factor-α (TNFα) before and after the CART procedures.

RESULTS

Body weight and waist circumference significantly decreased after CART (both p<0.001). Body temperature (BT) increased significantly at an average rate of 1.1°C during CART (p<0.001). The change in BT was correlated with EA and not interleukin IL6 or TNFα. The rise in BT was positively correlated with serum EA levels at baseline. The increase in BT was significantly higher in the group with high EA (≥0.37) than in the low EAA group (<0.37) (p=0.02). TNFα and serum IL6 levels in ascites were significantly increased during CART (both p<0.001). However, no significant differences in the EA, serum TNFα or IL6 levels were found in ascitic fluid before and after the CART procedures.

CONCLUSION

Although this discovery warrants further study, EA assay can indicate an increase in BT during effective CART in patients with cirrhosis and ascites.

Laser-cut-type versus braided-type covered self-expandable metallic stents for distal biliary obstruction caused by pancreatic carcinoma: a retrospective comparative cohort study

BACKGROUND/AIMS

Covered self-expandable metallic stents (CMSs) are widely used for malignant distal biliary obstructions (MDBOs) caused by pancreatic carcinoma. This study compared the efficacy and safety of the laser-cut-type and braided-type CMSs.

METHODS

To palliate MDBOs caused by pancreatic carcinoma, the laser-cut-type CMSs was used from April 2014 to March 2017, and the braided-type CMSs was used from April 2017 to March 2019. The tested self-expandable metallic stents were equipped with different anti-migration systems.

RESULTS

In total, 47 patients received CMSs for MDBOs (24 laser-cut type, 23 braided-type). The time to recurrent biliary obstruction (TRBO) was significantly longer in the braided-type CMSs (p=0.0008), and the median time to stent dysfunction or patient death was 141 and 265 days in the laser-cut-type CMSs and braided-type CMSs, respectively (p=0.0023). Stent migration was the major cause of stent dysfunction in both groups, which occurred in 37.5% of the laser-cut-type CMSs and 13.0% of the braidedtype CMSs. There were no differences in the survival duration between the groups.

CONCLUSION

The TRBO was significantly longer for the braided-type CMSs with an anti-migration system than for the laser-cuttype. Stent migration tended to be less frequent with the braided-type CMSs than with the laser-cut-type CMSs.

Ratio of von Willebrand factor antigen to ADAMTS13 activity is a useful biomarker for acute-on-chronic liver failure development and prognosis in patients with liver cirrhosis

AIM

Acute-on-chronic liver failure (ACLF) is associated with a high risk of short-term mortality after progression to multiple organ failure. A disintegrin-like and metalloproteinase with thrombospondin type-1 motifs 13 (ADAMTS13) is a metalloproteinase that specifically cleaves multimeric von Willebrand factor (VWF). An imbalance between ADAMTS13 enzyme and VWF substrate is associated with liver cirrhosis progression that induces ACLF. This study examined the relationship between ADAMTS13 and VWF and ACLF development to determine whether ADAMTS13 and VWF are useful predictive biomarkers for ACLF development and prognosis of patients with liver cirrhosis.

METHODS

The study enrolled 67 patients with Child-Pugh class A and B liver cirrhosis. ADAMTS13 activity (ADAMTS13:AC) and VWF antigen (VWF:Ag) were measured using enzyme-linked immunosorbent assays. The ratio of VWF:Ag to ADAMTS13:AC (VWF:Ag/ADAMTS13:AC) was used to divide patients into two groups according to the classification and regression tree based on Gray model survival analysis.

RESULTS

Compared with patients with Child-Pugh class A liver cirrhosis, class B patients had a higher VWF:Ag/ADAMTS13:AC and a higher risk of ACLF development. Cumulative incidence of ACLF was significantly higher in patients with high (>7.9) versus low (≤7.9) VWF:Ag/ADAMTS13:AC (hazard ratio [HR], 6.50; 95% CI, 2.31-18.29; p < 0.001). Cumulative survival was significantly lower in cirrhotic patients with high versus low VWF:Ag/ADAMTS13:AC (HR 5.11; 95% CI, 1.85-14.14; p = 0.002).

CONCLUSIONS

For patients with liver cirrhosis, VWF:Ag/ADAMTS13:AC is associated with functional liver reserve and predicts the development of ACLF and the prognosis.

Clinical Significance of Serum Zinc Levels on the Development of Sarcopenia in Cirrhotic Patients

BACKGROUND/AIM

Sarcopenia increases the mortality in patients with cirrhosis. Approximately 60% of zinc is accumulated in skeletal muscle. We aimed to determine the role of subclinical zinc deficiency on sarcopenia development in patients with cirrhosis.

PATIENTS AND METHODS

We enrolled 151 patients with cirrhosis and divided them into the group with normal serum zinc levels (Group N: 80-130 μg/dl; n=38) and group with subclinical zinc deficiency (Group D: <80 μg/dl; n=113). The risk factors for sarcopenia were then investigated.

RESULTS

Group D had more sarcopenia cases than Group N (31.0% vs. 13.2%). In group D, HGS exhibited a weakly positive but significant correlation with serum zinc levels (R=0.287, p=0.00212), serum zinc levels negatively correlated with both ammonia and myostatin levels (R=-0.254, p=0.0078; R=-0.33, p<0.01), and low zinc levels were independently associated with sarcopenia development.

CONCLUSION

Patients with cirrhosis showing subclinical zinc deficiency have a significantly higher risk of developing sarcopenia.

Results of the 𝚵− atomic X-ray measurement in J-PARC E07

Ξ− atomic X-ray spectroscopy is one of the most useful methods for investigation of the Ξ-nucleus strong interaction. A serious problem in the measurement is the significant background coming from in-flight Ξ− decay. For the first Ξ− atomic X-ray spectroscopy experiment, a novel method of identifying stopped Ξ− events using nuclear emulsion was developed to reject background photons from in-flight Ξ− decay. We succeeded in reducing the background to 1/170 by this method employing coincidence measurements using the nuclear emulsion and X-ray detectors.

Dual therapy with zinc acetate and rifaximin prevents from ethanol-induced liver fibrosis by maintaining intestinal barrier integrity

BACKGROUND

Hepatic overload of gut-derived lipopolysaccharide dictates the progression of alcoholic liver disease (ALD) by inducing oxidative stress and activating Kupffer cells and hepatic stellate cells through toll-like receptor 4 signaling. Therefore, targeting the maintenance of intestinal barrier integrity has attracted attention for the treatment of ALD. Zinc acetate and rifaximin, which is a nonabsorbable antibiotic, had been clinically used for patients with cirrhosis, particularly those with hepatic encephalopathy, and had been known to improve intestinal barrier dysfunction. However, only few studies focused on their efficacies in preventing the ALD-related fibrosis development.

AIM

To investigate the effects of a combined zinc acetate with rifaximin on liver fibrosis in a mouse ALD model.

METHODS

To induce ALD-related liver fibrosis, female C57BL/6J mice were fed a 2.5% (v/v) ethanol-containing Lieber-DeCarli liquid diet and received intraperitoneal carbon tetrachloride (CCl₄) injection twice weekly (1 mL/kg) for 8 wk. Zinc acetate (100 mg/L) and/or rifaximin (100 mg/L) were orally administered during experimental period. Hepatic steatosis, inflammation and fibrosis as well as intestinal barrier function were evaluated by histological and molecular analyses. Moreover, the direct effects of both agents on Caco-2 barrier function were assessed by in vitro assays.

RESULTS

In the ethanol plus CCl₄-treated mice, combination of zinc acetate and rifaximin attenuated oxidative lipid peroxidation with downregulation of Nox2 and Nox4. This combination significantly inhibited the Kupffer cells expansion and the proinflammatory response with blunted hepatic exposure of lipopolysaccharide and the toll-like receptor 4/nuclear factor kB pathway. Consequently, liver fibrosis and hepatic stellate cells activation were efficiently suppressed with downregulation of Mmp-2, -9, -13, and Timp1. Both agents improved the atrophic changes and permeability in the ileum, with restoration of tight junction proteins (TJPs) by decreasing the expressions of tumor necrosis factor α and myosin light chain kinase. In the in vitro assay, both agents directly reinforced ethanol or lipopolysaccharide-stimulated paracellular permeability and upregulated TJPs in Caco-2 cells.

CONCLUSION

Dual therapy with zinc acetate and rifaximin may serve as a strategy to prevent ALD-related fibrosis by maintaining intestinal barrier integrity.

Angiotensin Receptor Blockers Potentiate the Protective Effect of Branched-Chain Amino Acids on Skeletal Muscle Atrophy in Cirrhotic Rats

SCOPE

This study investigated the combined effect of the angiotensin II (AT-II) receptor blocker losartan and branched-chain amino acids (BCAAs) on skeletal muscle atrophy in rats with cirrhosis and steatohepatitis.

METHOD AND RESULTS

Fischer 344 rats are fed a choline-deficient l-amino acid-defined (CDAA) diet for 12 weeks and treated with oral losartan (30 mg kg^-1 day^-1 ) and/or BCAAs (Aminoleban EN, 2500 mg kg^-1 day^-1 ). Treatment with losartan and BCAAs attenuated hepatic inflammation and fibrosis and improved skeletal muscle atrophy and strength in CDAA-fed rats. Both agents reduced intramuscular myostatin and pro-inflammatory cytokine levels, resulting in inhibition of the ubiquitin-proteasome system (UPS) through interference with the SMAD and nuclear factor-kappa B pathways, respectively. Losartan also augmented the BCAA-mediated increase of skeletal muscle mass by promoting insulin growth factor-I production and mitochondrial biogenesis. Moreover, losartan decreased the intramuscular expression of transcription factor EB (TFEB), a transcriptional inducer of E3 ubiquitin ligase regulated by AT-II. In vitro assays illustrated that losartan promoted mitochondrial biogenesis and reduced TFEB expression in AT-II-stimulated rat myocytes, thereby potentiating the inhibitory effects of BCAAs on the UPS and caspase-3 cleavage.

CONCLUSION

These results indicate that this regimen could serve as a novel treatment for patients with sarcopenia and liver cirrhosis.

The Combination of Albumin-Bilirubin Score and Prothrombin Time Is a Useful Tool for Predicting Liver Dysfunction after Transcatheter Arterial Chemoembolization in Child-Pugh Class A Patients with Hepatocellular Carcinoma within Up-to-Seven Criteria

Mortality and recurrence rates of hepatocellular carcinoma (HCC) are high. Recent studies show that for patients with HCC beyond up-to-seven criteria, treatment with molecular-targeted agents (MTAs) is recommended because the treatment efficiency of transcatheter arterial chemoembolization (TACE) is poor; further, TACE increases decline in liver function. However, the relationship between TACE and liver function decline in patients with HCC within up-to-seven criteria has not been clarified. Hence, we aimed to investigate this relationship. This retrospective observational study included 189 HCC tumors within up-to-seven criteria in 114 Child–Pugh class A patients. Twenty-four (12.7%) tumors were changed from Child–Pugh class A to B after TACE, and 116 (61.4%) tumors exhibited recurrence within 6 months after TACE. Prothrombin time (PT) and albumin–bilirubin (ALBI) score before TACE were significantly associated with liver dysfunction from Child–Pugh class A to B. The combination of PT and ALBI score before TACE had high predictive ability for liver dysfunction from Child–Pugh class A to B after TACE (specificity = 100%, sensitivity = 91.7%). The combined use of pre-TACE PT and ALBI score has a high predictive ability for liver dysfunction after TACE for Child–Pugh class A patients with HCC within up-to-seven criteria.

Comparison of the efficacy and safety between palliative biliary stent placement and duct clearance among elderly patients with choledocholithiasis: a propensity score-matched analysis

Objectives

This study aimed to evaluate and compare the outcomes of palliative endoscopic biliary stenting (EBS) and complete stone removal among elderly patients with choledocholithiasis using propensity score matching.

Methods

From April 2012 to October 2017, 161 patients aged 75 years and older with choledocholithiasis underwent endoscopic retrograde cholangiopancreatography at our institution. Among them, 136 (84.5%) had complete stone removal, and 25 (15.5%) underwent palliative EBS without further intervention until symptom occurrence. The median age of the EBS group was significantly higher than that of the complete stone removal group. The proportion of patients with dementia, cerebral infarction, preserved gallbladder with gallstones, and surgically altered anatomy was higher in the EBS group than in the complete stone removal group. Propensity score matching was used to adjust for different factors. In total, 50 matched patients (n = 25 in each group) were analyzed.

Results

The median duration of cholangitis-free periods was significantly shorter in the EBS group (596 days) than in the complete stone removal group. About half of patients in the EBS group required retreatment and rehospitalization for cholangitis during the observation period. Cholangitis was mainly caused by stent migration. There was no significant difference in terms of mortality rate and procedure-related adverse events between the two groups. Death was commonly attributed to underlying diseases. However, one patient in the EBS group died due to severe cholangitis.

Conclusions

Palliative EBS should be indicated only to patients with choledocholithiasis who have a poor prognosis.

Enhanced liver fibrosis score as a surrogate of liver-related complications and mortality in primary biliary cholangitis

The presence of bridging fibrosis predicts survival of primary biliary cholangitis (PBC). This study aimed to compare serum parameters for the estimation of liver fibrosis and prediction of clinical outcomes in PBC.Out of 392 patients with PBC, 102 who underwent liver biopsy and in whom fibrosis indices, platelet count, hyaluronic acid, type IV collagen 7 second domain, procollagen type III amino-terminal peptide, tissue inhibitor of metalloproteinases 1, Mac-2 binding protein glycosylation isomer, N-terminal type III collagen propeptide levels; fibrosis index based on 4 factors, aspartate aminotransferase-to-platelet ratio index, and enhanced liver fibrosis (ELF) score were determined, were included. The correlation of histological stages based on both Scheuer and Nakanuma classifications with fibrosis indices was investigated. The Nakanuma system comprises grading for liver fibrosis and bile duct loss. Diagnostic performances of 10 fibrosis indices were evaluated to identify patients with poor prognosis. Moreover, correlations of those with PBC clinical manifestation and survival were also investigated.Enhances liver fibrosis (ELF) score had the highest correlation coefficient for liver fibrosis evaluated according to either the Scheuer or Nakanuma classification among 10 serum fibrosis indices. It also had the highest diagnostic performance in estimating Scheuer stage III and Nakanuma fibrosis score 2, both of which represent portal-bridging fibrosis. Patients with an ELF score of ≥10.0 had shorter survival and presented more frequently clinical complications than those with an ELF score of <10.0.ELF score determines the severity of liver fibrosis and predicts the occurrence of complications and survival in patients with PBC.

The association between sarcopenia and endotoxin in patients with alcoholic cirrhosis

We aimed to prospectively identify the risk factors of sarcopenia in patients with cirrhosis.Patients (n = 193) included in a discovery cohort (January 2011 and December 2014) were categorized into alcoholic (A1; n = 55) and non-alcoholic cirrhosis (NA; n = 138) groups, and those (n = 235) in a validation cohort (January 2015 to December 2019) were categorized into alcoholic (n = 92), non-alcoholic steatohepatitis-related (n = 27), and hepatitis C virus-related cirrhosis groups (n = 116). Skeletal muscle mass index (SMI) was determined using computed tomography (SMI-CT) and bioelectrical impedance analysis (SMI-BIA). Endotoxin activity (EA) was measured with an EA assay.SMI-CT correlated with grip strength in all the groups but significantly correlated with SMI-BIA of the men in group A1 (R = 0.64, P < .0001) and both sexes in group NA (male: R = 0.44, P = .0001; female: R = 0.35, P = .003). SMI-CT inversely correlated with the EA levels of the men in group A1 (R = -0.67, P < .0001) and myostatin levels in group NA (R = -0.53, P < .0001). Lower extremity SMI had a strong negative correlation with the EA levels of the men in group A1 (R = -0.58, P < .001), whereas upper extremity SMI showed an inverse trend with EA levels (R = -0.28, P = .08). SMI-CT also inversely correlated with the EA levels in groups A2 (R = -0.52, P = .003) and N (R = -0.67, P < .0001) and myostatin levels in group C (R = -0.65, P < .0001). Moreover, SMI-CT correlated with nutritional factors, including cholinesterase (R = 0.50, P = .005), zinc (R = 0.45, P = .01), branched amino acid-to-tyrosine ratio (R = 0.39, P = .02), and triglyceride (R = 0.33, P = .03) in group N.Sarcopenia risk factors differ among cirrhosis etiologies. Alcohol-induced, intestine-mediated peripheral endotoxemia could participate in sarcopenia development in patients with alcoholic cirrhosis.

First Direct Measurement of an Astrophysical p-Process Reaction Cross Section Using a Radioactive Ion Beam

We have performed the first direct measurement of the ^{83}Rb(p,γ) radiative capture reaction cross section in inverse kinematics using a radioactive beam of ^{83}Rb at incident energies of 2.4 and 2.7A  MeV. The measured cross section at an effective relative kinetic energy of E_{cm}=2.393  MeV, which lies within the relevant energy window for core collapse supernovae, is smaller than the prediction of statistical model calculations. This leads to the abundance of ^{84}Sr produced in the astrophysical p process being higher than previously calculated. Moreover, the discrepancy of the present data with theoretical predictions indicates that further experimental investigation of p-process reactions involving unstable projectiles is clearly warranted.

Clinical Significance of Gamma-Glutamyltranspeptidase Combined with Carbohydrate-Deficient Transferrin for the Assessment of Excessive Alcohol Consumption in Patients with Alcoholic Cirrhosis

Background: This study aimed to compare the diagnostic performance of carbohydrate-deficient transferrin (CDT) and gamma-glutamyltranspeptidase (γ-GTP) to assess the single and combined benefits of these biological markers for the detection of chronic excessive alcohol consumption in patients with alcoholic cirrhosis. Methods: Biological markers were determined in blood samples from patients with alcoholic cirrhosis (drinking group, n = 35; nondrinking group, n = 81). The prediction accuracy of %CDT alone, γ-GTP alone, and their combination for the detection of excessive alcohol consumption was determined in patients with alcoholic cirrhosis. Results: Serum total bilirubin, alanine aminotransferase, aspartate aminotransferase, γ-GTP, and alkaline phosphatase levels and %CDT were significantly higher and serum albumin levels were significantly lower in the drinking group than in the nondrinking group. The combination of %CDT and γ-GTP compared with %CDT or γ-GTP alone showed a higher prediction accuracy. The combination of %CDT and γ-GTP exhibited a higher specificity than γ-GTP alone. However, in terms of sensitivity, no significant difference was found between single or combined markers. Conclusions: The combination of %CDT and γ-GTP is considered a useful biomarker of chronic excessive alcohol consumption in patients with alcoholic cirrhosis.

Intestinal Permeability Is a Mechanical Rheostat in the Pathogenesis of Liver Cirrhosis

Recent studies have suggested that an alteration in the gut microbiota and their products, particularly endotoxins derived from Gram-negative bacteria, may play a major role in the pathogenesis of liver diseases. Gut dysbiosis caused by a high-fat diet and alcohol consumption induces increased intestinal permeability, which means higher translocation of bacteria and their products and components, including endotoxins, the so-called "leaky gut". Clinical studies have found that plasma endotoxin levels are elevated in patients with chronic liver diseases, including alcoholic liver disease and nonalcoholic liver disease. A decrease in commensal nonpathogenic bacteria including Ruminococaceae and Lactobacillus and an overgrowth of pathogenic bacteria such as Bacteroidaceae and Enterobacteriaceae are observed in cirrhotic patients. The decreased diversity of the gut microbiota in cirrhotic patients before liver transplantation is also related to a higher incidence of post-transplant infections and cognitive impairment. The exposure to endotoxins activates macrophages via Toll-like receptor 4 (TLR4), leading to a greater production of proinflammatory cytokines and chemokines including tumor necrosis factor-alpha, interleukin (IL)-6, and IL-8, which play key roles in the progression of liver diseases. TLR4 is a major receptor activated by the binding of endotoxins in macrophages, and its downstream signal induces proinflammatory cytokines. The expression of TLR4 is also observed in nonimmune cells in the liver, such as hepatic stellate cells, which play a crucial role in the progression of liver fibrosis that develops into hepatocarcinogenesis, suggesting the importance of the interaction between endotoxemia and TLR4 signaling as a target for preventing liver disease progression. In this review, we summarize the findings for the role of gut-derived endotoxemia underlying the progression of liver pathogenesis.

Zinc Administration and Improved Serum Markers of Hepatic Fibrosis in Patients with Autoimmune Hepatitis

AIM

The aim of the present study is to investigate the effect of long-term zinc supplementation, which is important for the activation of various enzymes that contribute to antioxidant and antifibrotic activities, on the improvement of serum fibrotic markers in patients with autoimmune hepatitis (AIH).

METHODS

A total of 38 patients with AIH under regular treatment at our hospital who provided their consent for being treated with polaprezinc (75 mg twice daily) were included and classified into 2 groups: the patients with zinc elevation (n = 27) and the patients without zinc elevation (n = 11). Serum biomarker of fibrosis, protein expression levels of matrix metalloproteinases (MMPs), and their inhibitors (TIMPs) were evaluated.

RESULTS

A significant difference was found between the variability of serum procollagen type Ⅲ and collagen type Ⅳ-7S between the 2 groups before and after zinc administration for more than 24 months (p = 0.043 and p = 0.049). In the patients with zinc elevation, no significant changes were found in collagenase (MMP-1 and MMP-13) before and after zinc administration, whereas a significant increase in the expression of gelatinase (MMP-2 and MMP-9) was found after administration (p = 0.021 and p = 0.005). As for the relative ratio of MMPs to TIMPs, only MMP-9 to TIMP-1 showed a significant increase (p = 0.004).

CONCLUSIONS

Long-term treatment with polaprezinc has been demonstrated to safely improve serum fibrosis indices through increases in MMP-2/-9 and MMP-9/TIMP-1 and is expected to be well combined with direct antifibrotic therapies such as molecularly targeted agents.

Lenvatinib prevents liver fibrosis by inhibiting hepatic stellate cell activation and sinusoidal capillarization in experimental liver fibrosis

Molecular targeted agents are pharmacologically used to treat liver fibrosis and have gained increased attention. The present study examined the preventive effect of lenvatinib on experimental liver fibrosis and sinusoidal capillarization as well as the in vitro phenotypes of hepatic stellate cells. LX-2, a human stellate cell line, was used for in vitro studies. In vivo liver fibrosis was induced in F344 rats using carbon tetrachloride by intraperitoneal injection for 8 weeks, and oral administration of lenvatinib was started two weeks after initial injection of carbon tetrachloride. Lenvatinib restrained proliferation and promoted apoptosis of LX-2 with suppressed phosphorylation of extracellular signal-regulated kinase 1/2 and AKT. It also down-regulated COL1A1, ACTA2 and TGFB1 expressions by inhibiting the transforming growth factor-β1/Smad2/3 pathway. Treatment with lenvatinib also suppressed platelet-derived growth factor-BB-stimulated proliferation, chemotaxis and vascular endothelial growth factor-A production, as well as basic fibroblast growth factor-induced LX-2 proliferation. In vivo study showed that lenvatinib attenuated liver fibrosis development with reduction in activated hepatic stellate cells and mRNA expression of profibrogenic markers. Intrahepatic neovascularization was ameliorated with reduced hepatic expressions of Vegf1, Vegf2 and Vegfa in lenvatinib-treated rats. Collectively, these results suggest the potential use of lenvatinib as a novel therapeutic strategy for liver fibrosis.

Association between ADAMTS13 activity–VWF antigen imbalance and the therapeutic effect of HAIC in patients with hepatocellular carcinoma

BACKGROUND

Prediction of HAIC treatment response is important for improving the prognosis in patients with hepatocellular carcinoma (HCC). The progression of HCC is related to hypercoagulability and angiogenesis. It is known that ADAMTS13 and von Willebrand factor (VWF) are related to hypercoagulability. In addition, previous study reported that the association between ADAMTS13 and VWF, and angiogenesis via vascular endothelial growth factor (VEGF). Recently, ADAMTS13 and VWF have been associated with the prognosis in patients with various kinds of cancer undergoing chemotherapy.

AIM

To investigate whether ADAMTS13 and VWF become useful biomarkers of treatment response in HCC patients before the initiation of HAIC treatment.

METHODS

Seventy-two patients were enrolled in this study. ADAMTS13 activity (ADAMTS13:AC), VWF antigen (VWF:Ag) and VEGF levels were determined via enzyme-linked immunosorbent assay. Univariable and multivariable analyses were performed to determine the predictive factors of treatment response in patients with HCC undergoing HAIC treatment.

RESULTS

ADAMTS13:AC levels in HCC patients with stable disease (SD) + partial response (PR) of HAIC treatment were significantly higher than those with progressive disease (PD) (P < 0.05). In contrast, VWF:Ag/ADAMTS13:AC ratio and VEGF levels in HCC patients with SD + PR were significantly lower than those with PD (both P < 0.05). Patients with high VWF:Ag/ADAMTS13:AC ratio (> 2.7) had higher VEGF levels than those with low ratio (≤ 2.7). Multivariable analysis revealed that VWF:Ag/ADAMTS13:AC ratio was a predictive factor of HAIC treatment response.

CONCLUSION

VWF:Ag/ADAMTS13:AC ratio may become a useful biomarker of treatment response in HCC patients before the initiation of HAIC treatment.

Role of Hepatitis E Virus Infection in North American Patients With Severe Acute Liver Injury

INTRODUCTION

The aim of this study was to determine the role of hepatitis E virus (HEV) infection in a large cohort of prospectively enrolled patients with severe acute liver injury (ALI).

METHODS

Serum samples from 594 consecutive adults enrolled between 2008 and 2018 in the US Acute Liver Failure Study Group ALI registry were tested for anti-HEV IgM and anti-HEV IgG levels. Those with detectable anti-HEV IgM underwent further testing for HEV RNA using real-time polymerase chain reaction.

RESULTS

The median age of patients was 38 years; 41% were men and 72% Caucasian. Etiologies of ALI included acetaminophen hepatotoxicity (50%), autoimmune hepatitis (8.9%), hepatitis B virus (8.9%), and idiosyncratic drug-induced liver injury (7.9%). Overall, 62 patients (10.4%) were negative for anti-HEV IgM but positive for IgG, whereas only 3 men (0.5%) were positive for both anti-HEV IgM and IgG. These 3 cases were initially diagnosed as having indeterminate, HEV, and hepatitis B virus-related ALI. One of these patients had detectable HEV RNA genotype 3, and another anti-HEV IgM+ patient had detectable HEV antigens by immunohistochemistry on liver biopsy. On multivariate modeling, older (odds ratio: 1.99) and non-Caucasian subjects (odds ratio: 2.92) were significantly more likely to have detectable anti-HEV IgG (P < 0.0001).

DISCUSSION

Acute HEV infection is an infrequent cause of ALI in hospitalized North American adults. The anti-HEV IgG+ patients were significantly older and more likely to be non-Caucasian. These data are consistent with other population-based studies that indicate exposure to HEV in the general US population is declining over time and might reflect a cohort effect.

Accuracy of Fibrosis-4 Index in Identification of Patients with Cirrhosis Who Could Potentially Avoid Variceal Screening Endoscopy

A potential restriction of the Baveno VI consensus, which helps to avoid unnecessary endoscopies, is the limited availability of FibroScan. We aimed to identify serum fibrosis indices that might aid in ruling out the presence of high-risk varices in cirrhotic patients. This retrospective study included 541 consecutive patients with cirrhosis who underwent endoscopy and had data available for nine serum fibrosis indices, including platelet count, hyaluronic acid, 7S fragment of type 4 collagen, procollagen type III N-terminal peptide, tissue inhibitor of metalloproteinases 1, Mac-2 binding protein glycosylation isomer, fibrosis index based on four factors (FIB-4), aspartate transaminase/platelet ratio index and enhanced liver fibrosis score. Optimal index cutoffs for predicting high-risk varices were calculated in an estimation cohort (n = 127) and evaluated in a validation cohort (n = 351). The diagnostic performance of the indices was assessed by receiver operating characteristic curve analysis. In the estimation cohort, a FIB-4 cutoff of 2.78 provided the greatest diagnostic accuracy in predicting both all-grade and high-risk varices. FIB-4 had a negative predictive value of 1.00 for high-risk varices in both cohorts, and 21.3% (27/127) and 14.8% (52/351) of the estimation and validation cohorts, respectively, avoided esophagogastroduodenoscopy; no high-risk varices were missed in either cohort. FIB-4 correctly identifies the absence of high-risk varices in patients with cirrhosis. Therefore, those with a FIB-4 of ≥2.78 should undergo esophagogastroduodenoscopy, and FIB-4 determination should be recommended every 6-12 months concurrently with the other blood tests until the index value reaches 2.78 in those with a FIB-4 of <2.78.

Effective Combination Therapy of Angiotensin-II Receptor Blocker and Rifaximin for Hepatic Fibrosis in Rat Model of Nonalcoholic Steatohepatitis

The progression of nonalcoholic steatohepatitis (NASH) is complicated. The multiple parallel-hits theory is advocated, which includes adipocytokines, insulin resistance, endotoxins, and oxidative stress. Pathways involving the gut–liver axis also mediate the progression of NASH. Angiotensin-II receptor blockers (ARB) suppress hepatic fibrosis via the activation of hepatic stellate cells (HSCs). Rifaximin, a nonabsorbable antibacterial agent, is used for the treatment of hepatic encephalopathy and has been recently reported to improve intestinal permeability. We examined the inhibitory effects on and mechanism of hepatic fibrogenesis by combining ARB and rifaximin administration. Fischer 344 rats were fed a choline-deficient/l-amino acid-defined (CDAA) diet for 8 weeks to generate the NASH model. The therapeutic effect of combining an ARB and rifaximin was evaluated along with hepatic fibrogenesis, the lipopolysaccharide–Toll-like receptor 4 (TLR4) regulatory cascade, and intestinal barrier function. ARBs had a potent inhibitory effect on hepatic fibrogenesis by suppressing HSC activation and hepatic expression of transforming growth factor-β and TLR4. Rifaximin reduced intestinal permeability by rescuing zonula occludens-1 (ZO-1) disruption induced by the CDAA diet and reduced portal endotoxin. Rifaximin directly affect to ZO-1 expression on intestinal epithelial cells. The combination of an ARB and rifaximin showed a stronger inhibitory effect compared to that conferred by a single agent. ARBs improve hepatic fibrosis by inhibiting HSCs, whereas rifaximin improves hepatic fibrosis by improving intestinal permeability through improving intestinal tight junction proteins (ZO-1). Therefore, the combination of ARBs and rifaximin may be a promising therapy for NASH fibrosis.

Distinct disease features in chimpanzees infected with a precore HBV mutant associated with acute liver failure in humans

Transmission to chimpanzees of a precore hepatitis B virus (HBV) mutant implicated in acute liver failure (ALF) in humans did not cause ALF nor the classic form of acute hepatitis B (AHB) seen upon infection with the wild-type HBV strain, but rather a severe AHB with distinct disease features. Here, we investigated the viral and host immunity factors responsible for the unusual severity of AHB associated with the precore HBV mutant in chimpanzees. Archived serial serum and liver specimens from two chimpanzees inoculated with a precore HBV mutant implicated in ALF and two chimpanzees inoculated with wild-type HBV were studied. We used phage-display library and next-generation sequencing (NGS) technologies to characterize the liver antibody response. The results obtained in severe AHB were compared with those in classic AHB and HBV-associated ALF in humans. Severe AHB was characterized by: (i) the highest alanine aminotransferase (ALT) peaks ever seen in HBV transmission studies with a significantly shorter incubation period, compared to classic AHB; (ii) earlier HBsAg clearance and anti-HBs seroconversion with transient or undetectable hepatitis B e antigen (HBeAg); (iii) limited inflammatory reaction relative to hepatocellular damage at the ALT peak with B-cell infiltration, albeit less extensive than in ALF; (iv) detection of intrahepatic germline antibodies against hepatitis B core antigen (HBcAg) by phage-display libraries in the earliest disease phase, as seen in ALF; (v) lack of intrahepatic IgM anti-HBcAg Fab, as seen in classic AHB, but at variance with ALF; and (vi) higher proportion of antibodies in germline configuration detected by NGS in the intrahepatic antibody repertoire compared to classic AHB, but lower than in ALF. This study identifies distinct outcome-specific features associated with severe AHB caused by a precore HBV mutant in chimpanzees, which bear closer resemblance to HBV ALF than to classic AHB. Our data suggest that precore HBV mutants carry an inherently higher pathogenicity that, in addition to specific host factors, may play a critical role in determining the severity of acute HBV disease.