Liver cirrhosis

Wnt/beta-catenin signaling and its modulators in nonalcoholic fatty liver diseases

Nonalcoholic fatty liver disease (NAFLD) is a global health concern associated with significant morbidity and mortality. NAFLD is a spectrum of diseases originating from simple steatosis, progressing through nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis that may lead to hepatocellular carcinoma (HCC). The pathogenesis of NAFLD is mediated by the triglyceride accumulation followed by proinflammatory cytokines expression leading to inflammation, oxidative stress, and mitochondrial dysfunction denoted as "two-hit hypothesis", advancing with a "third hit" of insufficient hepatocyte proliferation, leading to the increase in hepatic progenitor cells contributing to fibrosis and HCC. Wnt/β-catenin signaling is responsible for normal liver development, regeneration, hepatic metabolic zonation, ammonia and drug detoxification, hepatobiliary development, etc., maintaining the overall liver homeostasis. The key regulators of canonical Wnt signaling such as LRP6, Wnt1, Wnt3a, β-catenin, GSK-3β, and APC are abnormally regulated in NAFLD. Many experimental studies have shown the aberrated Wnt/β-catenin signaling during the NAFLD progression and NASH to hepatic fibrosis and HCC. Therefore, in this review, we have emphasized the role of Wnt/β-catenin signaling and its modulators that can potentially aid in the inhibition of NAFLD.

Prevalence of Spontaneous Bacterial Peritonitis (SBP) in Hepatitis B (HBV), and Hepatitis C (HCV) Liver Cirrhosis: A Systematic Review and Meta-Analysis

Background and Aim: Spontaneous bacterial peritonitis (SBP) is a common infection in liver cirrhosis. This systematic review and meta-analysis provide detailed information on the prevalence of SBP among hepatitis B virus (HBV) and hepatitis C virus (HCV)-related liver cirrhosis globally. Methods: A systematic search for articles describing the prevalence of SBP in HBV and HCV-related cirrhosis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Our search returned ten (10) eligible articles involving 1713 viral cirrhosis cases representing eight (8) countries. A meta-analysis was performed on our eligible studies using the random effect model. A protocol was registered with PROSPERO (CRD42022321790). Results: The pooled prevalence of SBP in HBV-associated cirrhosis had the highest estimate [8.0% (95% CI, 2.7−21.0%; I2 = 96.13%; p < 0.001)], followed by SBP in HCV-associated liver cirrhosis [4.0% (95% CI, 1.3%−11.5%; I2 = 88.99%; p < 0.001)]. China (61.8%, CI: 57.1−66.3%), the USA (50.0%, CI: 34.6−65.4%), and Holland (31.1%, CI: 21.6−42.5%) had the highest estimate for SBP in HBV associated liver cirrhosis, SBP in HCV associated liver cirrhosis and SBP in HBV + HCV associated liver cirrhosis respectively. There was a significant difference in the prevalence of SBP in viral hepatitis-associated liver cirrhosis with the year of sampling and method of SBP detection at P < 0.001. There was an increase in SBP incidence at the beginning of 2016 across the liver cirrhosis in this study. Conclusion: The findings of this review revealed a rise in the incidence of SBP in viral hepatitis over the last decade. The latter indicates a possible future rise in the global prevalence of SBP among HBV and HCV-related liver cirrhosis.

Exploration of the Severity of Hepatic Encephalopathy Deterioration Process Through Dynamics of the EEG Band Power time series

Cirrhosis is a liver disease that could impair the functionality of the neural system, limiting cognitive processes and reduce mobility, possibly because alterations on dynamics of neural communications. In this study the dynamics of band power fluctuations on ß and γ bands were studied on three groups: control, patients with cirrhosis and patients diagnosed with minimal hepatic encephalopathy. EEG signals were recorded on an oddball paradigm and analyzed to obtain the latency and amplitude of the P300 wave and Detrended Fluctuation Analysis (DFA) exponent values over ß and γ band power time series for each channel. As expected, the latency of the P300 wave was significantly different for control subjects ( ). Amplitudes were not as different, but they tend to decrease for cirrhosis and minimal hepatic encephalopathy groups. DFA exponent values also tends to describe a more regular process and seems to be related with presence of symptoms of hepatic encephalopathy. These subtle changes could be produced by the mechanisms of a mild neurological impairment and be used, if it is confirmed, as an index to evaluate such deterioration.

Ascites of Unexplained Origin: A Case Report

Ascites is defined as a massive collection of fluid in the peritoneal cavity, and it is most commonly caused by portal hypertension due to liver cirrhosis, acute liver failure, and heart failure. We report a case of ascites in a 39-year-old male who presented to the ED complaining of abdominal distention, sporadic pain on the epigastric area, unintentional weight loss over the past two months, night sweats, and blood-mixed stool. We conducted several imaging investigations and laboratory studies and none of them revealed any significant findings except for the abdominal CT with contrast, which showed large ascites along with submucosal fat deposition in the long segment of the transverse colon, suggestive of chronic inflammation [probably inflammatory bowel disease (IBD)], omental caking, and thickening. Peritoneal malignancy was highly suspected.

A diagnostic/therapeutic paracentesis was performed, through which 8 L of fluid was drained. Cytology was also performed and this showed mostly reactive mesothelial cells, negative acid-fast bacilli (AFB) culture, and negative polymerase chain reaction (PCR). We also discuss the other investigations performed, none of which helped in establishing a diagnosis.

Diagnostic efficacy of noninvasive liver fibrosis indexes in predicting portal hypertension in patients with cirrhosis

Background

Recent data suggest that noninvasive liver fibrosis indexes could be useful for predicting esophageal varices (EV) in cirrhotic patients. However, thus far, the diagnostic efficacy of these indexes in predicting portal hypertension (PH) in cirrhotic patients has been poorly evaluated.

Aims

To evaluate the diagnostic efficacy of noninvasive liver fibrosis indexes in the diagnosis of PH.

Methods

A total of 238 cirrhotic patients underwent hepatic venous pressure gradient (HVPG) evaluation and relevant serum tests to analyze the variables associated with PH grade. Then, the diagnostic performances of seven fibrosis indexes, the aspartate aminotransferase (AST)-to-alanine aminotransferase (ALT) ratio (AAR), AST-to-platelet (PLT) ratio index (APRI), fibrosis index (FI), FIB-4, Forns index, King’s score and the Lok index, were evaluated to determine their efficacy in predicting clinically significant PH (CSPH) and severe PH (SPH). In addition, the performances of these fibrosis indexes in different subgroups were investigated.

Results

The results of a multivariate analysis of serum markers showed that AST values, platelet (PLT) count and albumin (ALB) were associated with PH grade. Among the seven—fibrosis indexes, King’s score, APRI and the Lok index showed modest diagnostic accuracy in predicting CSPH and SPH, as indicated by AUC of 0.755 and 0.742, 0.740 and 0.742, and 0.722 and 0.717, respectively. In addition, combination of King’s score (cutoff 23.47) and Lok index (cutoff 1.30) predicted presence of CSPH, with the highest PPV (95.38%) and +LR (5.49). A subgroup analysis indicated that the noninvasive screening model may be more applicable to patients with cirrhosis of viral etiology.

Conclusions

Serum liver fibrosis indexes exhibited modest diagnostic accuracy for PH in cirrhotic patients. These indexes may not be able to replace HVPG measurements for the diagnosis of PH but may be used as a first-line screening method for CSPH in liver cirrhosis patients.

Decreased excitability and voltage-gated sodium currents in aortic baroreceptor neurons contribute to the impairment of arterial baroreflex in cirrhotic rats

Cardiovascular autonomic dysfunction, which is manifested by an impairment of the arterial baroreflex, is prevalent irrespective of etiology and contributes to the increased morbidity and mortality in cirrhotic patients. However, the cellular mechanisms that underlie the cirrhosis-impaired arterial baroreflex remain unknown. In the present study, we examined whether the cirrhosis-impaired arterial baroreflex is attributable to the dysfunction of aortic baroreceptor (AB) neurons. Biliary and nonbiliary cirrhotic rats were generated via common bile duct ligation (CBDL) and intraperitoneal injections of thioacetamide (TAA), respectively. Histological and molecular biological examinations confirmed the development of fibrosis in the livers of both cirrhotic rat models. The heart rate changes during phenylephrine-induced baroreceptor activation indicated that baroreflex sensitivity was blunted in the CBDL and TAA rats. Under the current-clamp mode of the patch-clamp technique, cell excitability was recorded in DiI-labeled AB neurons. The number of action potential discharges in the A- and C-type AB neurons was significantly decreased because of the increased rheobase and threshold potential in the CBDL and TAA rats compared with sham-operated rats. Real-time PCR and Western blotting indicated that the NaV1.7, NaV1.8, and NaV1.9 transcripts and proteins were significantly downregulated in the nodose ganglion neurons from the CBDL and TAA rats compared with the sham-operated rats. Consistent with these molecular data, the tetrodotoxin-sensitive NaV currents and the tetrodotoxin-resistant NaV currents were significantly decreased in A- and C-type AB neurons, respectively, from the CBDL and TAA rats compared with the sham-operated rats. Taken together, these findings implicate a key cellular mechanism in the cirrhosis-impaired arterial baroreflex.

The role of telomeres in liver disease

Telomeres stabilize open chromosome ends and protect them against chromosomal end-to-end fusions, breakage, instability, and nonreciprocal translocations. Telomere dysfunction is known to lead to an impaired regenerative capacity of hepatocytes and an increased cirrhosis formation in the context of acute and chronic liver injury. In addition, telomere dysfunction and telomerase mutations have been associated with the induction of chromosomal instability and consequently with cirrhosis development and hepatocarcinogenesis. The identification of molecular mechanisms related to telomere dysfunction and telomerase activation might lead to new therapeutic strategies. In this chapter, we are reviewing the current knowledge about the importance of telomere dysfunction in liver diseases.

Long-term outcome in patients with obscure gastrointestinal bleeding after capsule endoscopy

OBJECTIVE

This study aimed to identify the risk factors associated with rebleeding and long-term outcomes after capsule endoscopy (CE) for obscure gastrointestinal bleeding (OGIB) in a follow-up study.

METHODS

Data of consecutive patients who underwent CE due to OGIB from June 2002 to January 2012 were retrospectively reviewed. The Cox proportional hazard model was used to evaluate the risk factors associated with rebleeding, while Kaplan-Meier survival curves and the log-rank test were used to analyze cumulative rebleeding rates.

RESULTS

The overall rebleeding rate after CE in patients with OGIB was 28.6% (97/339) during a median follow-up of 48 months (range 12-112 months). Multivariate analysis showed that age ≥60 years (hazard ratio [HR] 2.473, 95% confidence interval [CI] 1.576-3.881, P = 0.000), positive CE findings (HR 3.393, 95% CI 1.931-5.963, P = 0.000), hemoglobin ≤70 g/L before CE (HR 2.010, 95% CI 1.261-3.206, P = 0.003), nonspecific treatments (HR 2.500, 95% CI 1.625-3.848, P = 0.000) and the use of anticoagulants, antiplatelet or non-steroidal anti-inflammatory drugs after CE (HR 2.851, 95% CI 1.433-5.674, P = 0.003) were independent risk factors associated with rebleeding. Univariate analysis showed that chronic hepatitis was independently associated with rebleeding in CE-negative patients (P = 0.021).

CONCLUSIONS

CE has a significant impact on the long-term outcome of patients with OGIB. Further investigation and close follow-up in patients with OGIB and those with negative CE findings are necessary.

Telomere shortening as genetic risk factor of liver cirrhosis

Cirrhosis is the main complication of chronic liver disease, leads to progressive liver function impairment and is the main risk factor for the development of liver cancer. Liver failure at endstage cirrhosis is associated with increased mortality with liver transplantation as the only possible treatment at this stage. The pathogenesis of liver cirrhosis is not completely elucidated. Although the common factors leading to liver injury, such as viral hepatitis, alcohol consume or fatty liver disease can be identified in the majority of patients a small percentage of patients have no apparent risk factors. Moreover given the same risk factors, some patients progress to cirrhosis whereas others have a benign course, the reason remains unclear. In order to develop new diagnostic and therapeutic tools, it is s essential to understand the pathogenesis of cirrhosis. The identification of genetic risk factors associated with cirrhosis is one of the possible approach to achieve these goal. In the past years several studies have supported the role of telomere shortening and cirrhosis. In the recent year several studies on the relation between several single nucleotide polymorphism (SNPs) and cirrhosis have been published; it has been proposed also a cirrhosis risk score based on seven SNPs. Also epidemiological studies on identical twins and in different ethnic groups have been supporting the importance of the role of genetic risk factors. Finally in the very recent years it has been suggested that telomere shortening may represent a genetic risk factor for the development of cirrhosis.

Assessment of serum acylated ghrelin in children and adolescents with chronic liver diseases: relation to nutritional status

Because ghrelin is one of the key hormones in regulating feeding behavior and caloric status, it was suggested that ghrelin behavior might be closely associated with malnutrition state of patients with chronic liver disease (CLD). Thus, we aimed to assess serum ghrelin levels in children with CLD and its relation to anthropometric parameters and severity of CLD. Forty CLD patients were studied in comparison to 40 controls. All subjects were subjected to history, anthropometric, and laboratory assessment of liver functions and serum acylated ghrelin. Ghrelin was higher in patients than controls being higher with progress of Child's grade and with deterioration of liver functions. Hyperghrelinemia was detected in 62.5% of cases. Ghrelin correlated negatively with body mass index standard deviation score (BMISDS (r = −0.95, P < 0.001)), triceps skin fold thickness (TSFT (r = −0.88, P < 0.001)), and subscapular skin fold thickness (SSFT (r = 0.83, P < 0.001)) percentiles. In conclusion, hyperghrelinemia may represent a compensatory mechanism trying to overcome malnutrition state complicating CLD and can be used as a parameter for early detection and assessment of the severity of malnutrition in children with CLD.

Telomere length in circulating serum DNA as a novel non-invasive biomarker for cirrhosis: a nested case-control analysis

BACKGROUND & AIMS

Previous studies have indicated that telomere length is associated with altered risk of various tumours including hepatitis B virus (HBV)-related hepatocellular carcinoma. However, the association between telomere length and the risk of cirrhosis has not been reported.

METHODS

In this nested case-control study, we used real-time quantitative PCR to determine the relative telomere length (RTL) in serum DNA samples from 100 HBV-related cirrhosis cases and 100 frequency-matched HBV controls, and evaluated the associations between RTL and cirrhosis risk by logistic regression analyses.

RESULTS

We found that cirrhotic cases had a significantly longer RTL (median, 0.36; range, 0.08-1.87) than non-cirrhotic controls (median, 0.20; range, 0.05-1.11) (P < 0.0001). Compared with subjects with short RTL, those with long RTL had a significantly increased cirrhosis risk [odds ratio, 2.76, 95% confidence interval, 1.50-5.10; P = 0.001]. Quartile analysis further indicated a dose-response effect for this association. Compared with patients with the lowest quartile of RTL, the cirrhosis risk for those with the second, third and highest quartile of RTL was 2.68 (0.91-7.87, P = 0.073), 3.37 (1.32-10.54, P = 0.013) and 6.64 (2.41-18.32, P < 0.0001) respectively (P(trend) <0.0001). Moreover, the area under the receiver operating characteristic curve increased from 0.60 (epidemiological variables) to 0.72 (epidemiological variables plus RTL), with statistically significant difference assessed by bootstrap analysis.

CONCLUSIONS

Our study presents the first epidemiological evidence that RTL in serum DNA could potentially be used as a simple, inexpensive and non-invasive marker of cirrhosis risk, a finding that warrants further investigations in independent retrospective and prospective populations.

Telomerase gene mutations are associated with cirrhosis formation

Telomere shortening impairs liver regeneration in mice and is associated with cirrhosis formation in humans with chronic liver disease. In humans, telomerase mutations have been associated with familial diseases leading to bone marrow failure or lung fibrosis. It is currently unknown whether telomerase mutations associate with cirrhosis induced by chronic liver disease. The telomerase RNA component (TERC) and the telomerase reverse transcriptase (TERT) were sequenced in 1,121 individuals (521 patients with cirrhosis induced by chronic liver disease and 600 noncirrhosis controls). Telomere length was analyzed in patients carrying telomerase gene mutations. Functional defects of telomerase gene mutations were investigated in primary human fibroblasts and patient-derived lymphocytes. An increased incidence of telomerase mutations was detected in cirrhosis patients (allele frequency 0.017) compared to noncirrhosis controls (0.003, P value 0.0007; relative risk [RR] 1.859; 95% confidence interval [CI] 1.552-2.227). Cirrhosis patients with TERT mutations showed shortened telomeres in white blood cells compared to control patients. Cirrhosis-associated telomerase mutations led to reduced telomerase activity and defects in maintaining telomere length and the replicative potential of primary cells in culture.

CONCLUSION

This study provides the first experimental evidence that telomerase gene mutations are present in patients developing cirrhosis as a consequence of chronic liver disease. These data support the concept that telomere shortening can represent a causal factor impairing liver regeneration and accelerating cirrhosis formation in response to chronic liver disease.

A mouse strain where basal connective tissue growth factor gene expression can be switched from low to high

Connective tissue growth factor (CTGF) is a signaling molecule that primarily functions in extracellular matrix maintenance and repair. Increased Ctgf expression is associated with fibrosis in chronic organ injury. Studying the role of CTGF in fibrotic disease in vivo, however, has been hampered by perinatal lethality of the Ctgf null mice as well as the limited scope of previous mouse models of Ctgf overproduction. Here, we devised a new approach and engineered a single mutant mouse strain where the endogenous Ctgf-3' untranslated region (3'UTR) was replaced with a cassette containing two 3'UTR sequences arranged in tandem. The modified Ctgf allele uses a 3'UTR from the mouse FBJ osteosarcoma oncogene (c-Fos) and produces an unstable mRNA, resulting in 60% of normal Ctgf expression (Lo allele). Upon Cre-expression, excision of the c-Fos-3'UTR creates a transcript utilizing the more stable bovine growth hormone (bGH) 3'UTR, resulting in increased Ctgf expression (Hi allele). Using the Ctgf Lo and Hi mutants, and crosses to a Ctgf knockout or Cre-expressing mice, we have generated a series of strains with a 30-fold range of Ctgf expression. Mice with the lowest Ctgf expression, 30% of normal, appear healthy, while a global nine-fold overexpression of Ctgf causes abnormalities, including developmental delay and craniofacial defects, and embryonic death at E10-12. Overexpression of Ctgf by tamoxifen-inducible Cre in the postnatal life, on the other hand, is compatible with life. The Ctgf Lo-Hi mutant mice should prove useful in further understanding the function of CTGF in fibrotic diseases. Additionally, this method can be used for the production of mouse lines with quantitative variations in other genes, particularly with genes that are broadly expressed, have distinct functions in different tissues, or where altered gene expression is not compatible with normal development.

Proteomics in liver fibrosis is more than meets the eye

Liver fibrosis is a serious health issue for many liver patients and is currently diagnosed using liver biopsy. The erroneous nature of this technique urges the search for better, noninvasive alternatives. In this regard, proteomics has been described as a useful biomarker discovery tool and has become increasingly applied in the study of liver fibrosis. Experimental and clinical studies have already provided deeper insights in the molecular pathways of liver fibrosis and even confirmed previous findings. Recent advances in proteomic strategies and tools enable multiple fractionation, multiple protein identifications and parallel analyses of multiple samples. Despite its increasing popularity, proteomics still faces certain pitfalls concerning preanalytical variability, protein coverage and statistic reliability. Proteomics is still evolving, but will undoubtedly contribute to a better understanding of the basics of the pathology and certainly offer opportunities in liver fibrosis diagnostics and therapeutics.

Antisocial behavioral syndromes and past-year physical health among adults in the United States: results from the National Epidemiologic Survey on Alcohol and Related Conditions

OBJECTIVE

To describe associations of DSM-IV antisocial personality disorder (ASPD), DSM-IV conduct disorder without progression to ASPD (CD-only), and syndromal antisocial behavior in adulthood without conduct disorder before age 15 years (AABS, not a DSM-IV diagnosis) with past-year physical health status and hospital care utilization in the general U.S. adult population.

METHOD

This report is based on the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (N = 43,093, response rate = 81%). Respondents were classified according to whether they met criteria for ASPD, AABS, CD-only, or no antisocial syndrome. Associations of antisocial syndromes with physical health status and care utilization were examined using normal theory and logistic regression.

RESULTS

ASPD and AABS were significantly but modestly associated with total past-year medical conditions, coronary heart and gastrointestinal diseases, and numbers of inpatient hospitalizations, inpatient days, emergency department visits, and clinically significant injuries (all p < .05). ASPD was also associated with liver disease, arthritis, and lower scores on the Medical Outcomes Study 12-Item Short-Form Health Survey, version 2 (SF-12v2) physical component summary, role physical, and bodily pain scales (all p < .05). AABS was associated with noncoronary heart disease, lower scores on the SF-12v2 general health and vitality scales, and, among men, arthritis (all p < .05). CD-only was associated with single but not multiple inpatient hospitalizations, emergency department visits, and clinically significant injuries (all p < .05).

CONCLUSIONS

Estimates of burden related to antisocial behavioral syndromes need to consider associated physical health problems. Prevention and treatment guidelines for injuries and common chronic diseases may need to address comorbid antisociality, and interventions targeting antisociality may need to consider general health status, including prevention and management of injuries and chronic diseases.

The levels of ghrelin, leptin, TNF-alpha, and IL-6 in liver cirrhosis and hepatocellular carcinoma due to HBV and HDV infection

Background/Aim. Malnutrition, a common problem in liver cirrhosis and HCC, may readily deteriorate the clinical functions with resultant poor prognosis. Beside the hyper catabolic state frequently encountered in chronic liver disease and HCC, anorexia and reduced food intake also worsen the malnutrition. The recently discovered peptide hormone ghrelin acts as a counterpart of leptin in regulation of food intake and fat utilization. The aim of the present study was to investigate the ghrelin and leptin levels in cirrhosis and HCC due to hepatitis B and D viruses, and the association of ghrelin and leptin with TNF-α, IL-6 and the severity of the disease. Materials and methods. We measured serum ghrelin, leptin, TNF-α, and IL-6 levels using specific immunoassay in 45 patients (23 cirrhosis, 22 HCC) with HBV and/or HDV and in 25 control subjects. Results. In comparison to controls, serum ghrelin, TNF-α, and IL-6 levels were significantly higher in cirrhosis and HCC (P < .05), whereas serum leptin levels were found decreased (P < .05). There was a positive correlation between ghrelin and TNF-α, and a negative correlation between leptin and TNF-α (P < .05). Conclusion. In cirrhosis and HCC due to HBV or HDV, serum ghrelin levels were increased with a corresponding decrease in serum leptin concentrations, acting as a physiological counterpart of ghrelin. The increasing of ghrelin is more prominent in Child C cirrhosis and the level was correlated with TNF-α. The presence of nutritional and metabolic abnormalities, including malnutrition, in cirrhosis and HCC may, at least partly, elucidate high ghrelin and low leptin levels.

A simple clinical score predicts high risk for upper gastrointestinal hemorrhages from varices in patients with chronic liver disease

OBJECTIVE

Upper gastrointestinal (GI) bleeding from esophageal or gastric fundus varices is a common complication of portal hypertension in liver cirrhosis and carries a high mortality rate of 20-35%. Stratifying high-risk patients for variceal bleeding is mainly based on endoscopic scoring. The purpose of this study was to develop a simple clinical score to assess the bleeding risk.

MATERIAL AND METHODS

A total of 111 patients with chronic liver diseases were included during evaluation for potential liver transplantation and were followed for 6 years. Findings at study entry were analyzed for their value in predicting hemorrhages.

RESULTS

Twenty-four patients (22%) developed upper GI hemorrhages from varices during the follow-up period. Common characteristics at study entry of patients with future bleedings included viral hepatitis or alcoholic etiology, advanced-stage cirrhosis, decreased liver function, impaired hemostasis and endoscopic presence of varices. These parameters were also independent predictors of bleedings. A four-item Bleeding Risk Score, including cholinesterase <2.25 kU/l, international normalized ratio (INR) >1.2, viral or alcoholic etiology and presence of varices, was used to identify patients at high (>2 points) or low (<or=2) risk of bleedings, and found superior in sensitivity and specificity to the Child-Pugh or MELD score.

CONCLUSIONS

A simple clinical score can predict the risk for upper GI bleedings in patients with chronic liver disease. This Bleeding Risk Score may help to supplement current endoscopic and clinical approaches to identify high-risk patients.

High adiponectin in chronic liver disease and cholestasis suggests biliary route of adiponectin excretion in vivo

BACKGROUND/AIMS

Models of fatty liver diseases and fibrosis suggest a hepatoprotective effect of adiponectin, an adipocyte-derived hormone with antidiabetic, antiobesity, antiatherogenic and anti-inflammatory effects.

METHODS

We studied adiponectin serum levels in 111 chronic liver disease (CLD) patients and 226 healthy controls and the impact of cholestasis on adiponectin by bile duct ligation experiments in mice.

RESULTS

Adiponectin was significantly elevated in CLD, and correlated with stage of liver cirrhosis, liver cell injury, e.g. aminotransferase activity, and inflammatory markers, but not with liver synthesis capacity, insulin sensitivity (HOMA index) or clinical complications. As patients with biliary liver diseases and cholestasis exhibited the highest adiponectin levels, we experimentally investigated a potential biliary route of adiponectin excretion. Following bile duct ligation in mice adiponectin levels rapidly increased without affecting hepatic adiponectin gene expression. Also, adiponectin was detectable in human bile. High adiponectin concentrations were associated with severe cholangitis and/or cholestasis on liver histology.

CONCLUSIONS

Adiponectin is elevated in chronic liver disease and correlates with inflammation and liver damage. High adiponectin levels after bile duct ligation in mice and in human bile from cholestatic patients suggest that biliary secretion is involved in adiponectin clearance and that adiponectin could serve as a novel marker indicating cholestasis in liver cirrhosis.

In vivo effects of Chinese herbal recipe, Danshaohuaxian, on apoptosis and proliferation of hepatic stellate cells in hepatic fibrotic rats

AIM

To investigate the effects of Danshaohuaxian (DSHX), a Chinese herbal recipe, on the apoptosis and cell cycles of hepatic stellate cells (HSCs) in rat hepatic fibrosis and its possible mechanisms.

METHODS

Seventy-six male Wistar rats were randomly divided into normal control group, hepatic fibrosis group, non-DSHX-treated group and DSHX-treated group. Except for the normal control group, rat hepatic fibrotic models were induced by subcutaneous injection of carbon tetrachloride (CCl4), drinking alcohol, giving diet of hyperlipid and hypoprotein for 8 wk. When the hepatic fibrotic models were produced, 12 rats of hepatic fibrosis group (15 rats survived, others died during the 8 wk) were sacrificed to collect blood and livers. HSCs were isolated from the other 3 rats to detect the apoptotic index (AI) and cell cycles by flow cytometry. DSHX was then given to the DSHX-treated group (1.0 g/kg, PO, daily) for 8 wk. At the same time, normal control group and non-DSHX-treated group were given normal saline for 8 wk. At end of the experiment, some rats in these three groups were sacrificed to collect blood and livers, the other rats were used for HSC isolation to detect the apoptotic index (AI) and cell cycles. Then the liver index, serum hyaluronic acid (HA) and alanine aminotransferase (ALT), degree of hepatic fibrosis, urinary excretion of hydroxyproline (Hyp) and expression of collagen types I and III (COL I and III) in these four groups were detected respectively.

RESULTS

Compared with the indexes of the hepatic fibrosis group and non-DSHX-treated group, the DSHX-treated group revealed a liver index of (0.0267+/-0.0017 vs 0.0423+/-0.0044, 0.0295+/-0.0019, P<0.05), levels of serum HA (200.78+/-31.71 vs 316.17+/-78.48, 300.86+/-72.73, P<0.05) and ALT (93.13+/-5.79 vs 174.5+/-6.02, 104.75+/-6.54, P<0.01), and stage of hepatic fibrosis (1.30 vs 4.25, 2.60, P<0.01) all reduced. The urinary excretion of Hyp increased (541.09+/-73.39 vs 62.00+/-6.40, 182.44+/-30.83, P<0.01), the COL I and III expression decreased (COL I: 1.07+/-0.96 vs 4.18+/-2.26, 3.22+/-1.44, P<0.01; COL III: 1.09+/-0.58 vs 3.04+/-0.62, 2.23+/-0.58, P<0.01), the HSCs apoptotic index of HSCs (7.81+/-0.47 vs 1.63+/-0.25, 1.78+/-0.4, P<0.05) and the ratio of G0-G1 phase cells increased (94.30+/-1.33 vs 62.27+/-17.96, 50.53+/-2.25, P<0.05). The ratios of S-phase cells (3.11+/-1.27 vs 9.83+/-1.81, 11.87+/-1.9, P<0.05) and G2-M phase cells (2.58+/-0.73 vs 23.26+/-10.95, 13.60+/-1.15, P<0.01) declined.

CONCLUSION

DSHX capsule shows certain therapeutic effects on hepatic fibrosis in rats and inhibits abnormal deposition of COL I and III in rat livers by promoting the apoptosis of HSCs and preventing their proliferation.

Quantitative hepatic phosphorus-31 magnetic resonance spectroscopy in compensated and decompensated cirrhosis

Few studies have examined the physiological/biochemical status of hepatocytes in patients with compensated and decompensated cirrhosis in situ. Phosphorus-31 magnetic resonance spectroscopy ((31)P MRS) is a noninvasive technique that permits direct assessments of tissue bioenergetics and phospholipid metabolism. Quantitative (31)P MRS was employed to document differences in the hepatic metabolite concentrations among patients with compensated and decompensated cirrhosis as well as healthy controls. All MRS examinations were performed on a 1.5-T General Electric Signa whole body scanner. The concentration of hepatic phosphorylated metabolites among patients with compensated cirrhosis (n = 7) was similar to that among healthy controls (n = 8). However, patients with decompensated cirrhosis (n = 6) had significantly lower levels of hepatic ATP compared with patients with compensated cirrhosis and healthy controls (P < 0.02 and P < 0.009, respectively) and a higher phosphomonoester/phosphodiester ratio than controls (P < 0.003). The results of this study indicate that metabolic disturbances in hepatic energy and phospholipid metabolism exist in patients with decompensated cirrhosis that are not present in patients with compensated cirrhosis or healthy controls. These findings provide new insights into the pathophysiology of hepatic decompensation.

Prevention of critical telomere shortening by oestradiol in human normal hepatic cultured cells and carbon tetrachloride induced rat liver fibrosis

BACKGROUND AND AIM

Significant telomere shortening of hepatocytes is associated with replicative senescence and a non-dividing state in chronic liver disease, resulting in end stage liver failure and/or development of hepatocellular carcinoma. To prevent critical telomere shortening in hepatocytes, we have focused on oestrogen dependent transactivation of the human telomerase reverse transcriptase (hTERT) gene as a form of telomerase therapy in chronic liver disease.

METHODS

We examined expression of hTERT mRNA and its protein, and telomerase activity (TA) in three human normal hepatic cell lines (Hc-cells, h-Nheps, and WRL-68) before and after treatment with 17beta-oestradiol. The effects of exogenous oestradiol administration were examined in a carbon tetrachloride (CCl(4)) induced model of liver fibrosis in rats.

RESULTS

Expression of hTERT mRNA and its protein was upregulated by oestradiol treatment. Telomere length decreased in Hc-cells and h-Nheps with accumulated passages whereas with long term oestradiol exposure it was greater than without oestradiol. The incidence of beta-galactosidase positive cells, indicating a state of senescence, decreased significantly in oestradiol treated cells in comparison with non-treated cells (p<0.05). TA in both male and female rats with CCl(4) induced liver fibrosis was significantly higher with oestradiol administration than without (p<0.05). Long term oestradiol administration markedly rescued the hepatic telomere from extensive shortening in both male and female rats.

CONCLUSION

These results suggest that oestradiol acts as a positive modulator of the hTERT gene in the liver. Oestrogen dependent transactivation of the hTERT gene is a new strategy for slowing the progression of chronic liver disease.

Analysis of factors contributing to higher erythropoietin levels in patients with chronic liver disease

BACKGROUND

Dysregulated erythropoietin (EPO) plasma levels may play a role in the pathophysiology of chronic liver disease (CLD) because chronic anaemia is frequently observed in patients with liver cirrhosis. We aimed to identify the factors contributing to EPO regulation in patients with CLD.

METHODS

Plasma EPO concentrations were correlated with clinical and laboratory parameters in 111 CLD patients and 220 healthy controls.

RESULTS

Anaemia, though generally mild, was common in CLD patients, and thrombocytopenia and previous bleeding episodes were observed in two-thirds of the patients. Plasma EPO levels were significantly elevated in CLD patients (P < 0.001). EPO increased according to Child's stages of cirrhosis, independently of the aetiology of CLD. EPO correlated with haemoglobin (r= -0.498, P < 0.001). Additionally, EPO independently correlated with markers of liver dysfunction, e.g. prothrombin time, albumin concentration or cholinesterase activity, and platelet count. EPO was also significantly elevated in patients with a current bleeding tendency and with prior gastrointestinal haemorrhages. EPO levels were increased in patients with impaired pulmonary function, e.g. decreased diffusion capacity, vital capacity or hyperventilation. Interestingly, plasma interleukin-6 (IL-6) concentrations positively correlated with EPO (r=0.277, P = 0.003), suggesting a possible mechanism of EPO upregulation in patients with CLD through IL-6 dependent pathways, e.g. binding of STAT transcription factors in the putative EPO promoter region.

CONCLUSIONS

EPO is upregulated in patients with chronic liver diseases in response to anaemia, bleeding complications, impaired pulmonary function, thrombocytopenia and liver dysfunction. IL-6 dependent pathways could be involved in mediating elevated EPO levels in CLD patients.

Hepatic 31P MRS in rat models of chronic liver disease: assessing the extent and progression of disease

BACKGROUND

Hepatic adenosine triphosphate (ATP) levels are an accurate reflection of functioning hepatic mass following surgical resections and acute liver injury.

OBJECTIVE

To determine whether hepatic ATP levels can serve as a non-invasive means of documenting progression of chronic liver disease to cirrhosis.

METHODS

In vivo phosphorus-31 magnetic resonance spectroscopy ((31)P MRS) was performed in three animal models of chronic liver disease. Sixty six adult Sprague- Dawley rats were subjected to either thioacetamide, carbon tetrachloride (CCl(4)), or common bile duct ligation (CBDL) to induce liver disease (n=35, 21, and 10, respectively). Serial MRS examinations, blood samples, and liver biopsies (when appropriate) were obtained throughout and/or on completion of the study.

RESULTS

Over the course of the chronic liver disease, a progressive decrease in hepatic ATP levels was consistently observed in each model. The findings were most striking when end stage liver disease (cirrhosis) was established. The reduction in hepatic ATP levels correlated with significant changes in serum albumin concentrations (CCl(4) and CBDL models) and the extent of hepatocyte loss seen histologically (all models).

CONCLUSION

The results of this study indicate that during progression of chronic liver disease to cirrhosis, there is a progressive reduction in hepatic ATP levels. In addition, changes in hepatic ATP levels correlate with changes in liver function and histology. Thus hepatic (31)P MRS provides a non-invasive means of documenting the severity and progression of parenchymal and cholestatic models of chronic liver disease in rats.

Ghrelin in chronic liver disease

BACKGROUND/AIMS

Ghrelin is a novel endogenous ligand for the growth hormone (GH) secretagogue receptor involved in energy metabolism, glucose homeostasis and food intake. We investigated the role of ghrelin and insulin-like growth factor-1 (IGF-1), the mediator of the GH axis, in patients with chronic liver diseases (CLD).

METHODS

Ghrelin and IGF-1 serum levels were determined in 105 CLD patients and 97 healthy controls and correlated with clinical and biochemical parameters.

RESULTS

Ghrelin was significantly elevated and IGF-1 reduced in CLD patients compared with healthy controls. IGF-1 serum levels inversely correlated with Child's classification. Ghrelin levels were significantly elevated in Child C cirrhosis patients independent of the aetiology of liver disease. Ghrelin levels did not correlate with liver function. In contrast, there was a correlation of ghrelin with clinical (gastrointestinal bleeding, ascites, encephalopathy) and biochemical (anaemia, inflammatory markers, hypoglycaemia, renal dysfunction) parameters. In a subgroup of patients with CLD and hepatocellular carcinoma (HCC), we observed a strong inverse correlation between alpha-fetoprotein (AFP) and ghrelin levels.

CONCLUSIONS

Unlike IGF-1, ghrelin is not correlated with liver function, but increases in Child C cirrhosis and with complications of CLD. The inverse correlation with AFP in HCC patients requires further studies on the potential impact of ghrelin on the pathogenesis of anorexia-cachexia syndrome.

Hepatocyte telomere shortening and senescence are general markers of human liver cirrhosis

Telomere shortening limits the number of cell divisions of primary human cells and might affect the regenerative capacity of organ systems during aging and chronic disease. To test whether the telomere hypothesis applies to human cirrhosis, the telomere length was monitored in cirrhosis induced by a broad variety of different etiologies. Telomeres were significantly shorter in cirrhosis compared with noncirrhotic samples independent of the primary etiology and independent of the age of the patients. Quantitative fluorescence in situ hybridization showed that telomere shortening was restricted to hepatocytes whereas lymphocytes and stellate cells in areas of fibrosis had significantly longer telomere reserves. Hepatocyte-specific telomere shortening correlated with senescence-associated beta-galactosidase staining in 84% of the cirrhosis samples, specifically in hepatocytes, but not in stellate cells or lymphocytes. Hepatocyte telomere shortening and senescence correlated with progression of fibrosis in cirrhosis samples. This study demonstrates for the first time that cell type-specific telomere shortening and senescence are linked to progression of human cirrhosis. These findings give a novel explanation for the pathophysiology of cirrhosis, indicating that fibrotic scarring at the cirrhosis stage is a consequence of hepatocyte telomere shortening and senescence. The data imply that future therapies aiming to restore regenerative capacity during aging and chronic diseases will have to ensure efficient targeting of specific cell types within the affected organs.

Adenovirus-mediated gene transfer to nonparenchymal cells in normal and injured liver

Adenovirus-mediated gene transfer has become an important tool with which to introduce genetic material into cells. Available data emphasize efficient adenoviral transduction of parenchymal liver cells (i.e., hepatocytes) in both in vitro and in vivo model systems, typically in normal cells. The aim of this study was to evaluate gene transfer to nonparenchymal (and parenchymal) cells of the normal and injured rat liver. Hepatocytes, stellate cells, and endothelial cells were isolated by standard methods. Liver injury was induced by bile duct ligation or carbon tetrachloride administration. Cells were transduced in vitro with an adenovirus encoding beta-galactosidase (Ad.beta-gal) over a range of viral titers, and transduced cells were identified by detection of X-gal. In vivo transduction efficiency was studied in normal and injured livers using cell isolation techniques. Nonparenchymal cells were transduced with greater frequency than hepatocytes at all adenoviral titers tested, both in vitro and in vivo. After liver injury, adenoviral transduction was reduced for all liver cell types compared with that for cells from normal livers (at all virus titers). Notably, transduction efficiency remained greater in nonparenchymal cells than in hepatocytes after liver injury. This work implies that, to achieve comparable gene expression in the injured liver, higher adenoviral titers may be required, an important consideration as gene therapy in disease states is considered.

Acquired portosystemic shunting in two cats

Acquired portosystemic shunts (PSS) are a clinical entity distinct from congenital PSS. Their apparent incidence in cats is low, which may reflect the rarity of predisposing hepatic parenchymal disease, such as cirrhosis, in this species. Two cats with acquired PSS associated with primary hepatobiliary disease are described. Relevant findings in acquired PSS are discussed, as are potential reasons for the apparently low incidence in the cat.

Tissue factor and thrombomodulin levels are correlated with stage of cirrhosis in patients with liver disease

Liver cirrhosis is associated with alterations of the coagulation system commonly causing bleeding as well as thromboembolic complications. The potential pathophysiological roles of tissue factor (TF) (the initiator of the extrinsic coagulation pathway) and thrombomodulin (TM) (an initiator of the anticoagulatory protein C pathway) are unknown. We therefore measured plasma concentrations of TF and TM in 111 patients with liver diseases who were evaluated for liver transplantation. We could demonstrate that the levels of both molecules increased with the Child's class of liver cirrhosis, independently of aetiology. TM was significantly elevated in Child A, B and C patients compared with patients without cirrhosis; TF only in Child C patients. The plasma TM and TF concentrations correlated with prothrombin time, activated partial thromboplastin time, and inversely with factor VII activity, cholinesterase serum activity, and serum albumin concentration. TM was elevated in patients with a bleeding tendency, but TM and TF did not differ between patients with or without prior thrombotic events. Further studies are warranted to clarify the underlying mechanisms that raise TM and TF plasma levels in liver disease with possible clinical consequences.

Fibrosis in undifferentiated (anaplastic) thyroid carcinomas: evidence for a dual action of tumour cells in collagen type I synthesis

The mechanisms involved in stromal reactions and fibrosis in solid malignant tumours are incompletely understood. In the present study, collagen type I production was investigated in tissues and cell lines derived from human undifferentiated (anaplastic) thyroid carcinomas, a highly aggressive, often fibrotic malignancy with mesenchymal phenotype. In situ hybridization showed the expression of pro-alpha1(I) collagen mRNA throughout the stromal part of the tumours. However, immunofluorescence staining using an anti-pro-collagen type I antibody revealed the synthesis of pro-collagen type I protein mainly in stromal cells juxtaposed to nests of tumour cells. In one out of five tissue samples from human undifferentiated thyroid carcinomas, pro-alpha1(I) collagen mRNA expression was also found in a small number of tumour cells. Several well-characterized cell lines established from undifferentiated thyroid carcinomas, two from tumours included in the present study, expressed both pro-alpha1(I) collagen and prolyl 4-hydroxylase mRNA, and three of these cell lines also synthesized native triple-helical collagen type I. Taken together, these data suggest that stromal fibroblasts are the main producers of collagen type I in anaplastic thyroid tumours. The carcinoma cells seem to play a regulatory role, stimulating the synthesis of collagen type I protein in the surrounding stroma by increasing pro-alpha1(I) collagen mRNA translation. However, collagen type I production by the carcinoma cells might also contribute to the marked desmoplasia commonly seen in these tumours.

Inhibition of experimental liver cirrhosis in mice by telomerase gene delivery

Accelerated telomere loss has been proposed to be a factor leading to end-stage organ failure in chronic diseases of high cellular turnover such as liver cirrhosis. To test this hypothesis directly, telomerase-deficient mice, null for the essential telomerase RNA (mTR) gene, were subjected to genetic, surgical, and chemical ablation of the liver. Telomere dysfunction was associated with defects in liver regeneration and accelerated the development of liver cirrhosis in response to chronic liver injury. Adenoviral delivery of mTR into the livers of mTR(-/-) mice with short dysfunctional telomeres restored telomerase activity and telomere function, alleviated cirrhotic pathology, and improved liver function. These studies indicate that telomere dysfunction contributes to chronic diseases of continual cellular loss-replacement and encourage the evaluation of "telomerase therapy" for such diseases.