by
Yugo Ando;
Guo-Xiang Yang;
Masanobu Tsuda;
Kazuhito Kawata;
Weici Zhang;
Takahiko Nakajima;
Koichi Tsuneyama;
Patrick Leung;
Zhe-Xiong Lian;
Kazuichi Okazaki;
William M. Ridgway;
Gary L. Norman;
Aftab A Ansari;
Xiao-Song He;
Ross L. Coppel;
M. Eric Gershwin
dnTGFβRII mice, expressing a dominant negative form of TGFβ receptor II under control of the CD4 promoter, develop autoimmune colitis and cholangitis . We previously observed that deficiency in IL-12p40 led to a marked diminution of inflammation in both the colon and the liver. To distinguish whether IL-12p40 mediated protection acted via the IL-12 or IL-23 pathways, we generated an IL-23p19−/− dnTGFβRII strain deficient in IL-23 but not in IL-12; mice were longitudinally followed for changes in the natural history of disease and immune responses. Interestingly, IL-23p19−/− mice demonstrate dramatic improvement in their colitis but no changes in biliary pathology; mice also manifest reduced Th17 cell populations and unchanged IFN-γ levels. We submit that the IL-12/Th1 pathway is essential for biliary disease pathogenesis, while the IL-23/Th17 pathway mediates colitis. To further assess the mechanism of the IL-23 mediated protection from colitis, we generated an IL-17A−/− dnTGFβRII strain deficient in IL-17, a major effector cytokine produced by IL-23-dependent Th17 cells. Deletion of the IL-17A gene did not affect the severity of either cholangitis or colitis, suggesting that the IL-23/Th17 pathway contributes to the colon disease in an IL-17-independent manner. These results affirm that the IL-12/Th1 pathway is critical to biliary pathology in dnTGFβRII mice while the colitis is caused by a direct effect of IL-23.
by
Robert H. Squires;
Anil Dhawan;
Estella Alonso;
Michael R. Narkewicz;
Benjamin L. Shneider;
Norberto Rodriguez-Baez;
Dominic Dell Olio;
Saul Karpen;
John Bucuvalas;
Steven Lobritto;
Elizabeth Rand;
Philip Rosenthal;
Simon Horslen;
Vicky Ng;
Girish Subbarao;
Nanda Kerkar;
David Rudnick;
M. James Lopez;
Kathleen Schwarz;
Rene Romero Jr.;
Scott Elisofon;
Edward Doo;
Patricia R. Robuck;
Sharon Lawlor;
Steven H. Belle
N-acetylcysteine (NAC) was found to improve transplantation-free survival in only those adults with non-acetaminophen (non-APAP) acute liver failure (ALF) and grade 1–2 hepatic encephalopathy (HE). Because non-APAP ALF differs significantly between children and adults, the Pediatric Acute Liver Failure (PALF) Study Group evaluated NAC in non-APAP PALF. Children from birth through age 17 years with non-APAP ALF enrolled in the PALF registry were eligible to enter an adaptively allocated, doubly masked, placebo-controlled trial using a continuous intravenous infusion of NAC (150 mg/kg/day in 5% dextrose in water [D5W]) or placebo (D5W) for up to 7 days. The primary outcome was 1-year survival. Secondary outcomes included liver transplantation-free survival, liver transplantation (LTx), length of ICU and hospital stays, organ system failure and maximum HE score. A total of 184 participants were enrolled in the trial with 92 in each arm. The 1-year survival did not differ significantly (p=0.19) between the NAC (73%) and placebo (82%) treatment groups. The 1-year LTx-free survival was significantly lower (p=0.03) in those who received NAC (35%) than those who received placebo (53%), particularly, but not significantly so, among those less than 2 years old with HE grade 0–1 (NAC 25%; placebo 60%; p=0.0493). There were no significant differences between treatment arms for hospital or ICU length of stay, organ systems failing, or highest recorded grade of HE.
Conclusion: NAC did not improve 1-year survival in non-APAP PALF. 1-year LTx-free survival was significantly lower with NAC, particularly among those < 2 years old. These results do not support broad use of NAC in non-APAP PALF and emphasizes the importance of conducting controlled pediatric drug trials, regardless of results in adults.
Hepatology published by Wiley Periodicals, Inc., on behalf of the American Association for the Study of Liver Diseases. Nonalcoholic fatty liver disease (NAFLD) is a burgeoning health problem worldwide and an important risk factor for both hepatic and cardiometabolic mortality. The rapidly increasing prevalence of this disease and of its aggressive form nonalcoholic steatohepatitis (NASH) will require novel therapeutic approaches to prevent disease progression to advanced fibrosis or cirrhosis and cancer. In recent years, bile acids have emerged as relevant signaling molecules that act at both hepatic and extrahepatic tissues to regulate lipid and carbohydrate metabolic pathways as well as energy homeostasis. Activation or modulation of bile acid receptors, such as the farnesoid X receptor and TGR5, and transporters, such as the ileal apical sodium-dependent bile acid transporter, appear to affect both insulin sensitivity and NAFLD/NASH pathogenesis at multiple levels, and these approaches hold promise as novel therapies. In the present review, we summarize current available data on the relationships of bile acids to NAFLD and the potential for therapeutically targeting bile-acid-related pathways to address this growing world-wide disease. (Hepatology 2017;65:350-362).
Nonalcoholic fatty liver disease (NAFLD) represents a burgeoning problem in hepatology, and is associated with insulin resistance. Exendin-4 is a peptide agonist of the glucagon-like peptide (GLP) receptor that promotes insulin secretion. The aim of this study was to determine whether administration of Exendin-4 would reverse hepatic steatosis in ob/ob mice. Ob/ob mice, or their lean littermates, were treated with Exendin-4 [10 μg/kg or 20 μg/kg] for 60 days. Serum was collected for measurement of insulin, adiponectin, fasting glucose, lipids, and aminotransferase concentrations. Liver tissue was procured for histological examination, real-time RT-PCR analysis and assay for oxidative stress. Rat hepatocytes were isolated and treated with GLP-1. Ob/ob mice sustained a reduction in the net weight gained during Exendin-4 treatment. Serum glucose and hepatic steatosis was significantly reduced in Exendin-4 treated ob/ob mice. Exendin-4 improved insulin sensitivity in ob/ob mice, as calculated by the homeostasis model assessment. The measurement of thiobarbituric reactive substances as a marker of oxidative stress was significantly reduced in ob/ob-treated mice with Exendin-4. Finally, GLP-1–treated hepatocytes resulted in a significant increase in cAMP production as well as reduction in mRNA expression of stearoyl-CoA desaturase 1 and genes associated with fatty acid synthesis; the converse was true for genes associated with fatty acid oxidation. In conclusion, Exendin-4 appears to effectively reverse hepatic steatosis in ob/ob mice by improving insulin sensitivity. Our data suggest that GLP-1 proteins in liver have a novel direct effect on hepatocyte fat metabolism.