Cholangiocyte endothelin 1 and transforming growth factor beta1 production in rat experimental hepatopulmonary syndrome

BACKGROUND & AIMS: Hepatic production and release of endothelin 1 plays a central role in experimental hepatopulmonary syndrome after common bile duct ligation by stimulating pulmonary endothelial nitric oxide production. In thioacetamide-induced nonbiliary cirrhosis, hepatic endothelin 1 production and release do not occur, and hepatopulmonary syndrome does not develop. However, the source and regulation of hepatic endothelin 1 after common bile duct ligation are not fully characterized. We evaluated the sources of hepatic endothelin 1 production after common bile duct ligation in relation to thioacetamide cirrhosis and assessed whether transforming growth factor beta1 regulates endothelin 1 production. METHODS: Hepatopulmonary syndrome and hepatic and plasma endothelin 1 levels were evaluated after common bile duct ligation or thioacetamide administration. Cellular sources of endothelin 1 were assessed by immunohistochemistry and laser capture microdissection of cholangiocytes. Transforming growth factor beta1 expression and signaling were assessed by using immunohistochemistry and Western blotting and by evaluating normal rat cholangiocytes. RESULTS: Hepatic and plasma endothelin 1 levels increased and hepatopulmonary syndrome developed only after common bile duct ligation. Hepatic endothelin 1 and transforming growth factor beta1 levels increased over a similar time frame, and cholangiocytes were a major source of each peptide. Transforming growth factor beta1 signaling in cholangiocytes in vivo was evident by increased phosphorylation and nuclear localization of Smad2, and hepatic endothelin 1 levels correlated directly with liver transforming growth factor beta1 and phosphorylated Smad2 levels. Transforming growth factor beta1 also stimulated endothelin 1 promoter activity, expression, and production in normal rat cholangiocytes. CONCLUSIONS: Cholangiocytes are a major source of hepatic endothelin 1 production during the development of hepatopulmonary syndrome after common bile duct ligation, but not in thioacetamide-induced cirrhosis. Transforming growth factor beta1 stimulates cholangiocyte endothelin 1 expression and production. Cholangiocyte-derived endothelin 1 may be an important endocrine mediator of experimental hepatopulmonary syndrome.     

Antiviral therapy after non-surgical tumor ablation in patients with hepatocellular carcinoma associated with hepatitis C virus

BACKGROUND: Antiviral therapy for chronic hepatitis C virus (HCV) infection has led to a reduction in the incidence of hepatocellular carcinoma (HCC). The purpose of the present paper was to assess whether antiviral therapy might suppress tumor recurrence and influence overall survival in patients with HCV-related HCC who had complete ablation of nodules by non-surgical treatments. METHODS: Twenty patients with three or fewer nodules of HCV-related HCC who were treated with percutaneous tumor ablation and/or transcatheter arterial embolization received combined interferon (IFN; 3 or 5 million units of IFN alpha-2b thrice weekly) plus ribavirin (1000-1200 mg per day) therapy for 24-48 weeks after complete ablation of lesions. During the same period, an additional 40 age- and sex-matched control patients with similar characteristics of tumors (sizes, numbers and treatment modalities) and severity of liver disease were recruited from the HCC database. Both recurrence-free survival and actuarial survival were evaluated. RESULTS: Of the 20 patients, 16 completed therapy and 10 showed a sustained response with normalization of alanine aminotransferase and negative HCV-RNA at 6 months after therapy completion. Due to severe side-effects experienced by Child B patients, who mostly discontinued antiviral therapy, clinical outcome was analyzed in the Child A treated (n = 16) and control (n = 33) patients. There was no significant difference in the incidence of local recurrence in sustained responders compared with non-responders or control patients (P = 0.174, 0.1284, respectively); but the second recurrence-free interval in the sustained responders was significantly longer than that of non-responders and the control group (P = 0.0141, 0.0243, respectively). Survival in sustained responders was better than in non-responders and control patients (P = 0.0691, 0.0554, respectively). CONCLUSIONS: These results indicate that successful antiviral therapy after non-surgical tumor ablation for HCV-related HCC may lower tumor recurrence rate and prolong survival.     

Many alphaIIbbeta3 autoepitopes in chronic immune thrombocytopenic purpura are localized to alphaIIb between amino acids L1 and Q459

In chronic immune thrombocytopenic purpura (ITP), autoantibodies bind to platelet surface proteins, particularly alphaIIb, resulting in platelet destruction by the reticulo-endothelial system. In order to better localize the autoepitopes on alphaIIb, we studied the binding of antibodies to Chinese hamster ovary (CHO) cells expressing either alphaIIbbeta3 or alphaIIb-alphavbeta3 chimaeras in which a segment of alphaIIb (either amino acids L1-Q459, L1-F223 or F223-Q459) was substituted for that portion of alphav. We evaluated platelet-associated autoantibodies from 14 ITP patients with alphaIIb-dependent antibodies. Ten of 14 bound to alphaIIb (L1-Q459)-alphavbeta3, showing that autoepitopes were often localized to this region of alphaIIb. In addition, each of the autoantibodies binding to alphaIIb (L1-Q459)-alphavbeta3, also bound to CHO cells expressing either alphaIIb(L1-F223)-alphavbeta3 or alphaIIb(F223-Q459)-alphavbeta3). In two of the three eluates tested, > 95% of the autoantibody binding to alphaIIb could be adsorbed using CHO cells expressing any of the three chimaeras, showing that the epitope(s) have contact points on either side of amino acid F223; in the third eluate, only a portion ( approximately 40%) could be adsorbed by the chimaeric cell lines showing that, in this patient, an additional antibody was also present, directed to a site distal to amino acid Q459. The remaining four eluates bound to CHO cells expressing alphaIIbbeta3 but to none of the chimaeras, suggesting that these epitopes are also distal to amino acid Q459. We conclude that the binding of many anti-alphaIIbbeta3 autoantibodies is dependent on the presence of alphaIIb amino acids L1-Q459.     

Pancreatitis-associated protein-I mRNA expression in mouse pancreas is upregulated by lipopolysaccharide independent of cerulein-pancreatitis

BACKGROUND AND AIMS: It is well known that endotoxemia, which is caused by a bacterial infection, can exacerbate acute pancreatitis, whereas pancreatitis-associated protein (PAP) has the ability to induce bacterial aggregation. Pancreatitis-associated protein is supposed to protect the tissue from infection during inflammation. In order to clarify the relationship between PAP mRNA expression and endotoxemia during acute pancreatitis, the kinetic patterns of PAP-I mRNA in mouse pancreas treated with either cerulein or lipopolysaccharide (LPS) or both were investigated in this study. METHODS AND RESULTS: The administration of LPS (5 mg/kg) intraperitoneally resulted in a dramatic upregulation of PAP-I mRNA expression, increasing 18.61-fold to a maximum at 12 h, then decreasing, but still sustaining at a high level and reaching baseline on day five. These changes were accompanied by the upregulation of tumor necrosis factor (TNF)-alpha, interleukin-1beta (IL-1beta), interleukin 6 (IL-6) and interferon gamma (IFNgamma) mRNA expressions in the pancreas, but not by marked alterations of serum amylase, lactic dehydrogenase (LDH) and histology. Cerulein also increased PAP-I mRNA expression. However, the combination of cerulein and LPS was not able to enhance PAP-I mRNA expression further, although more prominent pancreatitis based on significant changes of serum amylase, LDH and histology were observed. CONCLUSION: These results suggest that PAP-I mRNA might be modulated by endotoxemia, independent of cerulein-pancreatitis. There were no strong correlations between PAP-I mRNA expression and the severity of pancreatitis.     

The obesity paradox: body mass index and outcomes in patients with heart failure

BACKGROUND: In the general population, obesity is associated with increased risk of adverse outcomes. However, studies of patients with chronic disease suggest that overweight and obese patients may paradoxically have better outcomes than lean patients. We sought to examine the association of body mass index (BMI) and outcomes in stable outpatients with heart failure (HF). METHODS: We analyzed data from 7767 patients with stable HF enrolled in the Digitalis Investigation Group trial. Patients were categorized using baseline BMI (calculated as weight in kilograms divided by the square of height in meters) as underweight (BMI <18.5), healthy weight (BMI, 18.5-24.9, overweight (BMI, 25.0-29.9), and obese (BMI > or =30.0). Risks associated with BMI groups were evaluated using multivariable Cox proportional hazards models over a mean follow-up of 37 months. RESULTS: Crude all-cause mortality rates decreased in a near linear fashion across successively higher BMI groups, from 45.0% in the underweight group to 28.4% in the obese group (P for trend <.001). After multivariable adjustment, overweight and obese patients were at lower risk for death (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.80-0.96, and HR, 0.81; 95% CI, 0.72-0.92, respectively), compared with patients at a healthy weight (referent). In contrast, underweight patients with stable HF were at increased risk for death (HR 1.21; 95% CI, 0.95-1.53). CONCLUSIONS: In a cohort of outpatients with established HF, higher BMIs were associated with lower mortality risks; overweight and obese patients had lower risk of death compared with those at a healthy weight. Understanding the mechanisms and impact of the "obesity paradox" in patients with HF is necessary before recommendations are made concerning weight and weight control in this population.     

Cloning and identification of NS5ATP2 gene and its spliced variant transactivated by hepatitis C virus non-structural protein 5A

AIM: To clone, identify and study new NS5ATP2 gene and its spliced variant transactivated by hepatitis C virus non-structural protein 5A. METHODS: On the basis of subtractive cDNA library of genes transactivated by NS5A protein of hepatitis C virus, the coding sequence of new gene and its spliced variant were obtained by bioinformatics method. Polymerase chain reaction (PCR) was conducted to amplify NS5ATP2 gene. RESULTS: The coding sequence of a new gene and its spliced variant were cloned and identified successfully. CONCLUSION: A new gene has been recognized as the new target transactivated by HCV NS5A protein. These results brought some new clues for studying the biological functions of new genes and pathogenesis of the viral proteins.     

The effects of Chinese herb Angelica in focal cerebral ischemia injury in the rat

This experiment was designed to study the therapeutic mechanisms of Angelica on the focal cerebral ischemia injury of the rat. The ischemic area was determined by TTC stain. And terminal deoxynucleotidyl transferase (TDT) mediated DUTP-biotin nick end labeling (TUNEL) method was applied to detect neuronal apoptosis. The expressions of Bcl-2 and Bax proteins were observed by immunohistochemical staining methods. Results show that the treatment with angelica reduced the volume of cerebral infarction (p < 0.05), and that the number of neuronal apoptosis cells decreased significantly (p < 0.01). Also the expression level of Bax protein decreased (p < 0.01). These results suggest that Angelica can reduce the number of apoptosis cells by decreasing the expression of Bax protein. This is maybe one of the mechanisms of the therapeutic effect of Angelica on focal cerebral ischemia injury.