Plasma endothelin-1 levels in patients with biliary atresia: possible role in development of portal hypertension

A novel model based on immune-related genes for differentiating biliary atresia from other cholestatic diseases

PURPOSE

Based on a public gene expression database, this study established the immune-related genetic model that distinguished BA from other cholestasis diseases (DC) for the first time. We explored the molecular mechanism of BA based on the gene model.

METHODS

The BA microarray dataset GSE46960, containing BA, other cause of intrahepatic cholestasis than biliary atresia and normal liver gene expression data, was downloaded from the Gene Expression Omnibus (GEO) database. We performed a comprehensive bioinformatics analysis to establish and validate an immune-related gene model and subsequently identified hub genes as biomarkers associated with the molecular mechanisms of BA. To assess the model's performance for separating BA from other cholestasis diseases, we used receiver operating characteristic (ROC) curves and the area under the curve (AUC) of the ROC. Independent datasets GSE69948 and GSE122340 were used for the validation process.

RESULTS

The model was built using eight immune-related genes, including EDN1, HAMP, SAA1, SPP1, ANKRD1, MMP7, TACSTD2, and UCA1. In the GSE46960 and validation group, it presented excellent results, and the prediction accuracy of BA in comparison to other cholestasis diseases was good. Functional enrichment analysis revealed significant immunological differences between BA and other cholestatic diseases. Finally, we found that the TNFα-NF-κB pathway is associated with EDN1 gene expression and may explain fibrosis progression, which may become a new therapeutic target.

CONCLUSION

In summary, we have successfully constructed an immune-related gene model that can distinguish BA from other cholestatic diseases, while identifying the hub gene. Our exploration of immune genes provides new clues for the early diagnosis, molecular mechanism, and clinical treatment of biliary atresia.

The Role of Endothelin in the Pathophysiology of Migraine-a Systematic Review

PURPOSE OF REVIEW

Vasoactive peptides play a key role in the attack-initiating cascade of migraine. Recent studies have highlighted a potentially important role for endothelin-1, a potent vasoconstrictor peptide, in migraine pathophysiology. Here, we review the current data on endothelin's involvement in migraine.

RECENT FINDINGS

We identified 23 articles. Nine studies reported on endothelin-1 plasma concentrations in patients with migraine, eight studies investigated relevant genetic associations, five studies investigated endothelin-1 and spreading depression in animals, and one randomized controlled clinical trial tested the efficacy of an endothelin antagonist in the acute treatment of migraine in patients both with and without aura. Elevated endothelin-1 plasma levels have been reported in the early phase of migraine attacks. Genetic abnormalities related to the endothelin type A receptor have been reported in migraineurs. Endothelin-1 potently induces spreading depression in animals, which may explain the connection between endothelial irritation and migraine aura. Endothelin-1 could be a primary factor in the attack-triggering cascade of migraine attacks with and without aura. Additional studies in humans and animal models are needed to further elucidate the role of endothelin-1 in migraine.

Biliary Atresia Is Associated With Hypertension

OBJECTIVES

The improved survival of pediatric liver transplant recipients is accompanied by an increase in long-term comorbidities. A recently highlighted concern, hypertension, is associated with chronic kidney disease (CKD) in this population and can result in other target-organ damage during childhood. The prevalence of hypertension in pediatric liver transplantation is imprecisely known. In addition, individual etiologies of liver failure may convey different risks of hypertension. We sought to study the effect of liver transplantation on the prevalence of hypertension and CKD in patients with biliary atresia (BA).

METHODS

We conducted a retrospective chart review of 160 patients with BA followed at the Mount Sinai Medical Center, New York, from 1987 to 2012. Data were accumulated from the initial and subsequent visits at approximately 6 months, 1, 3, 5, 10, and 15 years of age. Hypertension was defined as systolic blood pressure >95th percentile for age, sex, height, and/or use of antihypertensive medication. Renal function was examined over time. Data were stratified by liver transplantation status at the time of visit.

RESULTS

A high prevalence of hypertension was observed from the initial visit through age 10, independent of transplant status (transplanted: 48% initial visit and 13% after 10 years vs nontransplanted: 55% initial visit and 17% after 10 years [P = ns for transplant status]). Mean estimated glomerular filtration rate (eGFR) was lower among liver transplant patients as compared with nontransplant patients and declined posttransplant. The incidence of CKD was higher among transplant patients.

CONCLUSIONS

Hypertension is common among children with BA, independent of liver transplant status. Transplant patients had significantly reduced renal function, which continued to decline over time. Hypertension was not associated with reduced eGFR.

NF-kappaB related abnormal hyper-expression of iNOS and NO correlates with the inflammation procedure in biliary atresia livers

OBJECTIVE

To study the expression of inducible nitric oxide synthase (iNOS) and its related regulators in biliary atresia (BA) livers and exlpore their relationships with the inflammation pathway in BA livers.

METHOD

The iNOS expression in livers of 38 cases of BA children, 15 cases of neonatal cholestasis (NC) children, and 18 cases of normal control were, respectively, examined and total nitric oxide (NO) metabolites concentration of all samples were calculated by a colorimetric method based on Griess reaction. The TdT-mediated dupt biotin nick end labeling (TUNEL) method was used to label the apoptotic bile duct epithelial cells and hepatocytes. The western blotting and immunohistochemistry methods to semi-quantitatively analyze the nuclear factor-kappaB (NF-kappaB) expression of each group were also used.

RESULTS

The iNOS expression intensity and total NO metabolites concentration of BA group (0.30 +/- 0.08, 90.40 +/- 12.46 micromol/L) were significantly higher than those of NC and normal control groups, P < 0.01. Correlation analysis showed a strong positive correlation between the serum AST level (152.76 +/- 29.59 U/L) and total NO metabolites concentration in BA group. Compared with the NC (32.47 +/- 5.55) and normal control (20.72 +/- 5.63) groups, a significantly higher apoptosis rate of intrahepatic bile duct epithelial cells was found in BA group (54.00 +/- 11.67) that tightly correlated with the iNOS intensity (r = 0.99, P < 0.01). The NF-kappaB intensity of BA group was also significantly higher than that of NC and normal control groups and had a strong positive correlation with the iNOS intensity (r = 0.97, P < 0.01).

CONCLUSION

The abnormal hyper-expression of iNOS may play an important role in mediating the inflammation procedure in BA livers. This change perhaps has some relationship with the high expression of NF-kappaB and NO. These regulators can up-regulate the apoptosis of bile duct epithelial cells in BA livers and cause the damage to liver tissues.

Paediatric cholestatic liver disease: Diagnosis, assessment of disease progression and mechanisms of fibrogenesis

Cholestatic liver disease causes significant morbidity and mortality in children. The diagnosis and management of these diseases can be complicated by an inability to detect early stages of fibrosis and a lack of adequate interventional therapy. There is no single gold standard test that accurately reflects the presence of liver disease, or that can be used to monitor fibrosis progression, particularly in conditions such as cystic fibrosis. This has lead to controversy over how suspected liver disease in children is detected and diagnosed. This review discusses the challenges in using commonly available methods to diagnose hepatic fibrosis and monitor disease progression in children with cholestatic liver disease. In addition, the review examines the mechanisms hypothesised to be involved in the development of hepatic fibrogenesis in paediatric cholestatic liver injury which may ultimately aid in identifying new modalities to assist in both disease detection and therapeutic intervention.

Serum vascular endothelial growth factor per platelet count in patients with biliary atresia

Background: Biliary atresia (BA) is a progressive, sclerosing, inflammatory process resulting in complete obliteration of the extrahepatic bile ducts. The obstruction of bile flow engenders worsening cholestasis, hepatic fibrosis, and cirrhosis, which lead to portal hypertension and a decline in hepatic synthetic function. Hepatic stellate cells, which play roles in hepatic fibrogenesis, are an important source of various inflammatory mediators including vascular endothelial growth factor (VEGF) in the injured liver. Objectives: Investigate the level of serum VEGF and serum VEGF per platelet count in patients with BA and its relation to clinical characteristics. Methods: Peripheral blood samples were taken from 70 BA patients and 15 healthy control children. Serum VEGF was measured by enzyme-linked immunosorbent assay. We compared serum VEGF and serum VEGF per platelet count in BA patients with the respective results obtained in healthy control children. The relation of serum VEGF per platelet count with clinical variables of BA patients was investigated. Results: Serum VEGF levels and serum VEGF per platelet count in BA patients were not significantly different from those in normal controls (289.64±230.01 pg/mL vs. 312.36±189.05 pg/mL; p=0.72 and 1.72±1.21x106 vs. 1.57±0.97x106; p=0.66). Significant differences were observed among BA patients when VEGF per platelet count was categorized by the presence of esophageal varice (p=0.03). Only in BA patients was the serum level of VEGF correlated with the number of platelets (r=0.53, p<0.001). Conclusion: A high serum VEGF per platelet count is a useful marker for the development of portal hypertension in BA patients, especially for esophageal varice. Serum VEGF per platelet count may be useful for monitoring disease course in BA after hepatic portoenterostomy.

Elevated serum macrophage migration inhibitory factor levels in post-operative biliary atresia

OBJECTIVE

Biliary atresia (BA) is one of the most common causes of neonatal cholestasis. Macrophage migration inhibitory factor (MIF) is an important mediator of inflammation and immune response in various diseases. The objective of this study was to examine the possible roles of MIF in BA.

METHODS

Forty-eight BA paediatric patients who had undergone a Kasai operation and 22 healthy children were recruited. The mean ages of the patients and controls were 8.47 +/- 0.74 and 7.64 +/- 0.41 years, respectively. The patients were categorised into two groups according to their serum levels of total bilirubin (TB) (TB < 2 mg/dL; no jaundice, and TB >/= 2 mg/dL; persistent jaundice). The serum MIF levels were determined using commercially available enzyme-linked immunosorbent assay.

RESULTS

The mean serum MIF level of the BA children was higher than that of healthy controls (0.43 +/- 0.04 ng/mL [corrected] vs. 0.27 +/- 0.02 ng/mL; [corrected] p < 0.001). However, there was no difference in serum MIF levels between BA patients with jaundice and those without jaundice. Further analysis revealed that there was no difference in serum MIF levels of BA patients without portal hypertension compared to that of BA patients with portal hypertension.

CONCLUSION

MIF production was elevated in BA patients compared to normal controls. It is likely that MIF plays a role in the pathophysiology of post-operative BA patients. However, the elevated MIF levels are not associated with either jaundice status or portal hypertension.

Overexpression of hepatic inducible nitric oxide synthase in biliary atresia

AIMS

Biliary atresia (BA) is a rare and serious liver disease in infants characterized by progressive inflammatory cholangiopathy. The aims of this study were to investigate hepatic expression of inducible nitric oxide synthase (iNOS) in BA and to associate the iNOS expression with their early therapeutic outcome.

METHODS

Hepatic iNOS expression was determined using immunohistochemistry from liver biopsies of 24 BA patients, and 16 non-BA patients whose liver tissues were needed in the treatment process. Six months after surgery, the BA patients were categorized into two groups;good and poor outcome. The iNOS expression of hepatocyte areas was evaluated based on its intensity using ImageJ software. Unpaired t-tests were used for the comparisons of iNOS expression between groups.

RESULTS

Hepatic iNOS expression of BA patients was significantly stronger than that of non-BA patients (P < 0.0001). The largest area of hepatic iNOS expression was the area of hepatocytes. Subgroup analysis of BA patients at 6 months post-op revealed that there was no difference in iNOS expression between the patients with good outcome and those with poor outcome (P = 0.732).

CONCLUSIONS

Overexpression of hepatic iNOS in BA patients was demonstrated. Within liver tissues, hepatocytes were the major source of hepatic iNOS production. However, the expression was not associated with the early therapeutic outcome. These results suggest that iNOS plays a role in the liver pathology of BA but its expression cannot be used as a predictor for therapeutic outcome.

Elevation of serum stem-cell factor in postoperative biliary atresia

BACKGROUND

Biliary atresia (BA) is one of the most common causes of neonatal cholestasis. Stem-cell factor (SCF) has been implicated in the development of fibrosis in various diseases. The objective of the present study was to examine the significant role of SCF in BA.

METHODS

Fifty-seven pediatric patients with BA after Kasai operation and 30 healthy children were recruited. The mean ages of BA patients and controls were 6.1 +/- 0.6 years and 6.1 +/- 0.7 years, respectively. The patients were categorized into two groups according to their serum levels of total bilirubin (TBil < 2 mg/dL, no jaundice vs TBil > or = 2 mg/dL, persistent jaundice) and alanine aminotransferase (ALT < 100 vs ALT > or = 100 U/L). The serum SCF levels were determined on commercially available enzyme-linked immunosorbent assay.

RESULTS

The mean serum SCF level of the BA children was higher than that of normal controls (748.3 +/- 17.9 pg/mL vs 582.2 +/- 17.3 pg/mL; P < 0.001). Subsequent analysis demonstrated that the BA patients with serum ALT > or = 100 U/L had significantly greater levels of serum SCF compared to those with serum ALT < 100 U/L (796.5 +/- 22.6 pg/mL vs 694.7 +/- 25.0 pg/mL, respectively; P = 0.002). In addition, serum SCF levels were significantly elevated in the patients with portal hypertension (PH) compared with those without PH (810.0 +/- 18.8 pg/mL vs 634.1 +/- 20.1 pg/mL, P < 0.001).

CONCLUSION

The current study showed that BA patients had higher serum SCF levels compared with controls. The significant elevation in SCF levels is associated with the presence of PH and the degree of hepatic injury. These findings suggest that SCF may play a part in the pathogenesis of hepatic fibrosis in BA patients after Kasai procedure.

Elevated serum nitric oxide metabolites in biliary atresia

Biliary atresia (BA) remains one of the most intractable liver diseases in children. The aim of this study was to investigate the possible roles of nitric oxide (NO) in BA. Serum levels of nitrite and nitrate (NO production) were determined using a colorimetric method from 65 post-operative BA patients and 12 healthy children. The patients were categorized into two groups according to their jaundice status, and serum alanine aminotransferase (ALT, a marker for liver injury). Unpaired t tests were used. Data are expressed as mean and SD in terms of mumol/l. Age and gender between BA patients and controls were comparable. Serum NO metabolites of BA patients was higher than the controls (79.77+/-21.22 vs. 65.75+/-9.44, P=0.001). Subgroup analysis revealed that there was no difference in serum nitrate/nitrite levels of BA patients without jaundice compared to those with jaundice (78.85+/-23.23 vs. 80.90+/-18.76, P=0.70). However, patients with serum ALT> or =100 IU/l had higher levels of serum NO metabolites compared to those with serum ALT<100 IU/l. In conclusion, NO production was elevated in BA patients compared to normal controls. Serum NO was associated with serum ALT levels, but not with jaundice status, in BA patients. These suggest that NO plays a role in the pathophysiology of liver injury in post-operative BA.