The LATS2 tumor suppressor inhibits SREBP and suppresses hepatic cholesterol accumulation.

The Hippo signaling pathway is a major regulator of organ size. In the liver, Hippo pathway deregulation promotes hyperplasia and hepatocellular carcinoma primarily through hyperactivation of its downstream effector, YAP. The LATS2 tumor suppressor is a core member of the Hippo pathway. A screen for LATS2-interacting proteins in liver-derived cells identified the transcription factor SREBP2, master regulator of cholesterol homeostasis. LATS2 down-regulation caused SREBP activation and accumulation of excessive cholesterol. Likewise, mice harboring liver-specific Lats2 conditional knockout (Lats2-CKO) displayed constitutive SREBP activation and overexpressed SREBP target genes and developed spontaneous fatty liver disease. Interestingly, the impact of LATS2 depletion on SREBP-mediated transcription was clearly distinct from that of YAP overexpression. When challenged with excess dietary cholesterol, Lats2-CKO mice manifested more severe liver damage than wild-type mice. Surprisingly, apoptosis, inflammation, and fibrosis were actually attenuated relative to wild-type mice, in association with impaired p53 activation. Subsequently, Lats2-CKO mice failed to recover effectively from cholesterol-induced damage upon return to a normal diet. Additionally, decreased LATS2 mRNA in association with increased SREBP target gene expression was observed in a subset of human nonalcoholic fatty liver disease cases. Together, these findings further highlight the tight links between tumor suppressors and metabolic homeostasis.

Tumors with intrahepatic bile duct differentiation in cirrhosis: implications on outcomes after liver transplantation.

BACKGROUND: The role of liver transplantation (LT) in the management of cirrhotic patients with tumors exhibiting intrahepatic bile duct differentiation remains controversial. The objective of this study was to characterize the spectrum of these tumors and analyze post-LT outcomes. METHODS: Retrospective pathology database search of explant histology analysis of liver transplants between April 1993 and November 2013. RESULTS: Thirty-two patients were analyzed, 75% were men with a mean age of 60 years. Seven patients had nodules demonstrating intrahepatic cholangiocarcinoma (I-CCA), nine had I-CCA nodules occurring concomitantly with hepatocellular carcinoma (HCC), and 16 had mixed HCC-CCA nodules. The median number of tumors was 1 and size was 2.5 cm. Overall patient survival post-LT at 1 and 5 years was 71% and 57%, respectively. Patients within Milan criteria, especially with I-CCA features, showed a 5-year tumor recurrence rate (10%) and 5-year survival rate (78%) comparable with other patients having HCC within Milan criteria. CONCLUSION: This series showed that patients with CCA within Milan criteria may be able to achieve acceptable long-term post-LT survival.

Clinical factors that predict noncirrhotic portal hypertension in HIV-infected patients: a proposed diagnostic algorithm.

Noncirrhotic portal hypertension (NCPH) is a rare but important clinical entity in human immunodeficiency virus (HIV) populations. The purpose of this study was to describe the clinical factors associated with the condition in an effort to formulate a diagnostic algorithm for easy and early diagnosis. We performed a multicenter, retrospective case-control study of 34 patients with NCPH and 68 control HIV patients. The study found that thrombocytopenia, splenomegaly, didanosine use, elevated aminotransferases, and an elevated alkaline phosphatase level were all significantly more prevalent in the NCPH cohort. Using these easily available clinical parameters, we developed an algorithm for early diagnosis of NCPH in HIV.

Regression of fibrosis and reversal of cirrhosis in rats by galectin inhibitors in thioacetamide-induced liver disease.

Galectin-3 protein is critical to the development of liver fibrosis because galectin-3 null mice have attenuated fibrosis after liver injury. Therefore, we examined the ability of novel complex carbohydrate galectin inhibitors to treat toxin-induced fibrosis and cirrhosis. Fibrosis was induced in rats by intraperitoneal injections with thioacetamide (TAA) and groups were treated with vehicle, GR-MD-02 (galactoarabino-rhamnogalaturonan) or GM-CT-01 (galactomannan). In initial experiments, 4 weeks of treatment with GR-MD-02 following completion of 8 weeks of TAA significantly reduced collagen content by almost 50% based on Sirius red staining. Rats were then exposed to more intense and longer TAA treatment, which included either GR-MD-02 or GM-CT-01 during weeks 8 through 11. TAA rats treated with vehicle developed extensive fibrosis and pathological stage 6 Ishak fibrosis, or cirrhosis. Treatment with either GR-MD-02 (90 mg/kg ip) or GM-CT-01 (180 mg/kg ip) given once weekly during weeks 8-11 led to marked reduction in fibrosis with reduction in portal and septal galectin-3 positive macrophages and reduction in portal pressure. Vehicle-treated animals had cirrhosis whereas in the treated animals the fibrosis stage was significantly reduced, with evidence of resolved or resolving cirrhosis and reduced portal inflammation and ballooning. In this model of toxin-induced liver fibrosis, treatment with two galectin protein inhibitors with different chemical compositions significantly reduced fibrosis, reversed cirrhosis, reduced galectin-3 expressing portal and septal macrophages, and reduced portal pressure. These findings suggest a potential role of these drugs in human liver fibrosis and cirrhosis.

Acute liver failure caused by 'fat burners' and dietary supplements: a case report and literature review.

Globally, people are struggling with obesity. Many effective, nonconventional methods of weight reduction, such as herbal and natural dietary supplements, are increasingly being sought. Fat burners are believed to raise metabolism, burn more calories and hasten fat loss. Despite patient perceptions that herbal remedies are free of adverse effects, some supplements are associated with severe hepatotoxicity. The present report describes a young healthy woman who presented with fulminant hepatic failure requiring emergent liver transplantation caused by a dietary supplement and fat burner containing usnic acid, green tea and guggul tree extracts. Thorough investigation, including histopathological examination, revealed no other cause of hepatotoxicity. The present case adds to the increasing number of reports of hepatotoxicity associated with dietary supplements containing usnic acid, and highlights that herbal extracts from green tea or guggul tree may not be free of adverse effects. Until these products are more closely regulated and their advertising better scrutinized, physicians and patients should become more familiar with herbal products that are commonly used as weight loss supplements and recognize those that are potentially harmful.

Insulin resistance predicts re-treatment failure in an efficacy study of peginterferon-α-2a and ribavirin in HIV/HCV co-infected patients.

BACKGROUND & AIMS: Few studies evaluated the efficacy of HCV re-treatment and the predictors of response in HIV/HCV co-infected patients. The role of insulin resistance as a predictor of response in this population is unknown. The aim of this study is to evaluate the safety and efficacy of pegylated interferon-α-2a and ribavirin in re-treatment of HIV/HCV co-infected patients, predictors of sustained virological response, including insulin resistance, and the relationship between insulin resistance and liver histology. METHODS: This prospective, multi-centered study included HIV/HCV co-infected patients with prior interferon-based treatment failure. Patients received pegylated interferon-α-2a and ribavirin for 48 weeks. Serum HCV RNA was measured 24 weeks post treatment to assess sustained virological response. Insulin resistance was defined as HOMA-IR >2. Correlations between baseline insulin resistance and steatosis, and/or cirrhosis were determined. RESULTS: Sustained virological response was achieved in 14/96 (15%) patients. 35% of patients with HOMA-IR < 2 (6/17) achieved sustained virological response vs 14% (5/36) of those with HOMA-IR between 2-4, and 7% (3/41) of those with HOMA-IR > 4 (p = 0.01). In multivariable analysis, insulin resistance and log10 HCV RNA were negatively associated with sustained virological response [AOR 0.17; 95% CI 0.05-0.64, p = 0.009, and AOR 0.36; 95% CI 0.14-0.93, p = 0.04, respectively]. Steatosis and cirrhosis correlated with insulin resistance (p = 0.02 and 0.03, respectively) but neither independently predicted sustained virological response. Discontinuations due to severe adverse events occurred in 8% of cases, and 2 patients died of unrelated causes. CONCLUSIONS: In HIV/HCV co-infected patients undergoing re-treatment, sustained virological response rate is low; those patients without insulin resistance are significantly more likely to achieve sustained virological response.

A system of classifying microvascular invasion to predict outcome after resection in patients with hepatocellular carcinoma.

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) recurs in approximately 70% of cases after resection. Vascular invasion by tumor cells can be classified as gross or microscopic (microvascular invasion [mVI]) and is a risk factor for recurrence. We examined a large cohort of patients with HCC who were treated by resection to identify features of mVI that correlated with recurrence and survival. METHODS: We reviewed the records of all HCC resections performed at the Mount Sinai School of Medicine between January 1990 and March 2006 to identify those with mVI, established by histologic analysis. The numbers and sizes of vessels invaded, invasion of a vessel with a muscular wall, distance from the tumor, and satellite nodules were recorded. RESULTS: Of the 384 patients who underwent resection for HCC, 131 (34.1%) met the entry criteria. The median follow-up period was 28.9 months. There were 68 recurrences and 54 deaths. In multivariate analysis, invasion of a vessel with a muscular wall predicted recurrence (hazard ratio, 1.8; P = .02), and invasion of a vessel with a muscular wall (hazard ratio, 2.2; P = .018) and invasion of a vessel that was more than 1 cm from the tumor (hazard ratio, 2.1; P = .015) predicted survival. A risk score that assigned points for the presence of each variable correlated with recurrence (P = .028) and survival (P < .0001). CONCLUSIONS: A novel classification system that includes invasion of a vessel with a muscular wall and invasion of a vessel that is more than 1 cm from the tumor can accurately predict risk of recurrence and survival of patients with mVI after resection of HCC.