Gut-pancreas-liver axis as a target for treatment of nafld/nash

Non-alcoholic fatty liver disease (NAFLD) represents the most common form of chronic liver disease worldwide. Due to its association with obesity and diabetes and the fall in hepatitis C virus morbidity, cirrhosis in NAFLD is becoming the most frequent indication to liver transplantation, but the pathogenetic mechanisms are still not completely understood. The so-called gut-liver axis has gained enormous interest when data showed that its alteration can lead to NAFLD development and might favor the occurrence of non-alcoholic steatohepatitis (NASH). Moreover, several therapeutic approaches targeting the gut-pancreas-liver axis, e.g., incretins, showed promising results in NASH treatment. In this review, we describe the role of incretin hormones in NAFLD/NASH pathogenesis and treatment and how metagenomic/metabolomic alterations in the gut microbiota can lead to NASH in the presence of gut barrier modifications favoring the passage of bacteria or bacterial products in the portal circulation, i.e., bacterial translocation.publishersversionpublishe

The Digital Underworld: Combating Crime on the Dark Web in the Modern Era

The Digital Underworld: Combating Crime on the Dark Web in the Modern Er

LPS-induced TNF-α factor mediates pro-inflammatory and pro-fibrogenic pattern in non-alcoholic fatty liver disease

Lipopolysaccharide (LPS) is currently considered one of the major players in non-alcoholic fatty liver disease (NAFLD) pathogenesis and progression. Here, we aim to investigate the possible role of LPS-induced TNF-α factor (LITAF) in inducing a pro-inflammatory and pro-fibrogenic phenotype of non-alcoholic steatohepatitis (NASH).We found that children with NAFLD displayed, in different liver-resident cells, an increased expression of LITAF which correlated with histological traits of hepatic inflammation and fibrosis. Total and nuclear LITAF expression increased in mouse and human hepatic stellate cells (HSCs). Moreover, LPS induced LITAF-dependent transcription of IL-1β, IL-6 and TNF-α in the clonal myofibroblastic HSC LX-2 cell line, and this effect was hampered by LITAF silencing. We showed, for the first time in HSCs, that LITAF recruitment to these cytokine promoters is LPS dependent. However, preventing LITAF nuclear translocation by p38MAPK inhibitor, the expression of IL-6 and TNF-α was significantly reduced with the aid of p65NF-ĸB, while IL-1β transcription exclusively required LITAF expression/activity. Finally, IL-1β levels in plasma mirrored those in the liver and correlated with LPS levels and LITAF-positive HSCs in children with NASH.In conclusion, a more severe histological profile in paediatric NAFLD is associated with LITAF over-expression in HSCs, which in turn correlates with hepatic and circulating IL-1β levels outlining a panel of potential biomarkers of NASH-related liver damage. The in vitro study highlights the role of LITAF as a key regulator of the LPS-induced pro-inflammatory pattern in HSCs and suggests p38MAPK inhibitors as a possible therapeutic approach against hepatic inflammation in NASH

Endoplasmic Reticulum stress induces hepatic stellate cell apoptosis and contributes to fibrosis resolution.

BACKGROUND: Survival of hepatic stellate cells (HSCs) is a hallmark of liver fibrosis, while the induction of HSC apoptosis may induce recovery. Activated HSC are resistant to many pro-apoptotic stimuli. To this issue, the role of Endoplasmic Reticulum (ER) stress in promoting apoptosis of HSCs and consequently fibrosis resolution is still debated. AIM: To evaluate the potential ER stress-mediated apoptosis of HSCs and fibrosis resolution METHODS: HSCs were incubated with the ER stress agonists, tunicamycin or thapsigargin. In vivo, HSC were isolated from normal, bile duct-ligated (BDL) and bile duct-diverted (BDD) rats. RESULTS: In activated HSC, the specific inhibitor of ER stress-induced apoptosis, calpastatin, is significantly increased vs. quiescent HSCs. Calpain is conversely reduced in activated HSCs. This pattern of protein expression provides HSCs resistance to the ER stress signals of apoptosis (apoptosis-resistant phenotype). However, both tunicamycin and thapsigargin are able to induce apoptosis in HSCs in vitro, completely reversing the calpain/calpastatin pattern expression. Furthermore, in vivo, the fibrosis resolution observed in rat livers subjected to bile duct ligation (BDL) and subsequent bile duct diversion (BDD), leads to fibrosis resolution through a mechanism of HSCs apoptosis, potentially associated with ER stress: in fact, BDD rat liver shows an increased number of apoptotic HSCs associated with reduced calapstatin and increased calpain protein expression, leading to an apoptosis-sensible phenotype. CONCLUSIONS: ER stress sensitizes HSC to apoptosis both in vitro and in vivo. Thus, ER stress represents a key target to trigger cell death in activated HSC and promotes fibrosis resolution

Prevalence and clinical outcome of hepatic haemangioma with specific reference to the risk of rupture: a large retrospective cross-sectional study.

BACKGROUND: Prevalence and incidence of hepatic haemangioma are estimated from autopsy series only. Although benign and generally asymptomatic, hepatic haemangioma can cause serious complications. AIMS: The aim of the study was to assess the prevalence of hepatic haemangioma and to attempt to quantify the risk of major complications such as spontaneous rupture. METHODS: We retrospectively analyzed the radiology database of a Regional University Hospital over a 7-year period: the radiological records of 83,181 patients who had an abdominal computed tomography or magnetic resonance scan were reviewed. Diagnoses made at imaging were reviewed and related to clinical course. RESULTS: Hepatic haemangioma was diagnosed in 2071 patients (2.5% prevalence). In 226 patients (10.9%), haemangioma had diameter of 4 cm or more (giant haemangioma). The risk of bleeding was assessed on patients without concomitant malignancies. Spontaneous bleeding occurred in 5/1067 patients (0.47%). All 5 patients had giant haemangioma: 4 had exophytic lesions and presented with haemoperitoneum; 1 with centrally located tumour experienced intrahepatic bleeding. CONCLUSION: Giant haemangiomas have a low but relevant risk of rupture (3.2% in this series), particularly when peripherally located and exophytic. Surgery might be considered in these cases

Clinical update on non-alcoholic fatty liver disease and steatohepatitis

clusion of less common causes of fatty liver such as Hepatitis B or C infection, drugs and autoimmune disorders, fatty liver is classified as non-alcoholic (NAFLD) or alcoholic fatty liver disease (AFLD) on the basis of daily ethanol intake. The agreed threshold of ethanol intake used to separate NAFLD from AFLD is 20 g/day, equivalent to 12 drinks per week. 2 The term NAFLD covers a wide spectrum of liver injury, ranging from simple steatosis, i.e. fatty infiltration of hepatocytes > 5%, to non-alcoholic steatohepatitis (NASH). At liver biopsy NASH is characterized by necro-inflammation and/or fibrosis, and is histologically indistinguishable from alcoholic steatohepatitis. The histological classification of NAFLD and NASH is being continuously improved and a refined scoring system has been recently proposed by the National Institutes of Health. 3 NAFLD is presently regarded as the most common liver disease in Western countries and virtually impacts all fields of clinical medicine, being considered a risk factor for advanced liver disease, type 2 diabetes and cardiovascular disease. Although NAFLD had long been recognized as a frequent clinical entity, only recently its importance as a potential cause of progressive and severe liver disease has been fully acknowledged. NAFLD prevalence in the general population ranges from 16 to 25% in adults 4 and from 10 to 19% in children. 5 It increases with age, shows different gender specificity according to geographic areas (generally more prevalent in women in US and viceversa in men in Europe and Japan) and varies with ethnicity, with the highest prevalence among the Hispanic population and the lowest among the AfroAmerican one. 6 Prevalence rates of NAFLD are strikingly increased in certain subpopulations, such as patients with obesity, type 2 diabetes mellitus and dyslipidemia, and the whole spectrum of NAFLD is commonly associated with the metabolic syndrome. The true prevalence of NASH remains largely unknown. According to data derived from autopsy or liver biopsy studies, about 10-15% of NAFLD patients meet the current diagnostic criteria for NASH, pointing to a prevalence of 2-3% in the general population. The incidence and natural course of NAFLD are also difficult to assess because most of the available studies are retrospective and/or performed on clinical series. The few prospective studies are too short to exclude late complications. While simple steatosis has a benign prognosis, NASH may progress to cirrhosis in 30% of cases and is responsible for liver-related death in 3-8%. In clinical series, up to 70% of patients with cryptogenic cirrhosis have clinical features suggestive of NASH.

Development and Validation of a New Prognostic System for Patients with Hepatocellular Carcinoma

BACKGROUND: Prognostic assessment in patients with hepatocellular carcinoma (HCC) remains controversial. Using the Italian Liver Cancer (ITA.LI.CA) database as a training set, we sought to develop and validate a new prognostic system for patients with HCC. METHODS AND FINDINGS: Prospective collected databases from Italy (training cohort, n = 3,628; internal validation cohort, n = 1,555) and Taiwan (external validation cohort, n = 2,651) were used to develop the ITA.LI.CA prognostic system. We first defined ITA.LI.CA stages (0, A, B1, B2, B3, C) using only tumor characteristics (largest tumor diameter, number of nodules, intra- and extrahepatic macroscopic vascular invasion, extrahepatic metastases). A parametric multivariable survival model was then used to calculate the relative prognostic value of ITA.LI.CA tumor stage, Eastern Cooperative Oncology Group (ECOG) performance status, Child-Pugh score (CPS), and alpha-fetoprotein (AFP) in predicting individual survival. Based on the model results, an ITA.LI.CA integrated prognostic score (from 0 to 13 points) was constructed, and its prognostic power compared with that of other integrated systems (BCLC, HKLC, MESIAH, CLIP, JIS). Median follow-up was 58 mo for Italian patients (interquartile range, 26-106 mo) and 39 mo for Taiwanese patients (interquartile range, 12-61 mo). The ITA.LI.CA integrated prognostic score showed optimal discrimination and calibration abilities in Italian patients. Observed median survival in the training and internal validation sets was 57 and 61 mo, respectively, in quartile 1 (ITA.LI.CA score 64 1), 43 and 38 mo in quartile 2 (ITA.LI.CA score 2-3), 23 and 23 mo in quartile 3 (ITA.LI.CA score 4-5), and 9 and 8 mo in quartile 4 (ITA.LI.CA score > 5). Observed and predicted median survival in the training and internal validation sets largely coincided. Although observed and predicted survival estimations were significantly lower (log-rank test, p < 0.001) in Italian than in Taiwanese patients, the ITA.LI.CA score maintained very high discrimination and calibration features also in the external validation cohort. The concordance index (C index) of the ITA.LI.CA score in the internal and external validation cohorts was 0.71 and 0.78, respectively. The ITA.LI.CA score's prognostic ability was significantly better (p < 0.001) than that of BCLC stage (respective C indexes of 0.64 and 0.73), CLIP score (0.68 and 0.75), JIS stage (0.67 and 0.70), MESIAH score (0.69 and 0.77), and HKLC stage (0.68 and 0.75). The main limitations of this study are its retrospective nature and the intrinsically significant differences between the Taiwanese and Italian groups. CONCLUSIONS: The ITA.LI.CA prognostic system includes both a tumor staging-stratifying patients with HCC into six main stages (0, A, B1, B2, B3, and C)-and a prognostic score-integrating ITA.LI.CA tumor staging, CPS, ECOG performance status, and AFP. The ITA.LI.CA prognostic system shows a strong ability to predict individual survival in European and Asian populations

HDL cholesterol protects from liver injury in mice with intestinal specific LXRα activation

Background and aims: Liver X receptors (LXRs) exert anti-inflammatory effects even though their hepatic activation is associated with hypertriglyceridemia and hepatic steatosis. Selective induction of LXRs in the gut might provide protective signal(s) in the aberrant wound healing response that induces fibrosis during chronic liver injury, without hypertriglyceridemic and steatogenic effects. Methods: Mice with intestinal constitutive LXRα activation (iVP16-LXRα) were exposed to intraperitoneal injection of carbon tetrachloride (CCl4) for 8 weeks, and in vitro cell models were used to evaluate the beneficial effect of high-density lipoproteins (HDL). Results: After CCl4 treatment, the iVP16-LXRα phenotype showed reduced M1 macrophage infiltration, increased expression M2 macrophage markers, and lower expression of hepatic pro-inflammatory genes. This anti-inflammatory effect in the liver was also associated with decreased expression of hepatic oxidative stress genes and reduced expression of fibrosis markers. iVP16-LXRα exhibited increased reverse cholesterol transport in the gut by ABCA1 expression and consequent enhancement of the levels of circulating HDL and their receptor SRB1 in the liver. No hepatic steatosis development was observed in iVP16-LXRα. In vitro, HDL induced a shift from M1 to M2 phenotype of LPS-stimulated Kupffer cells, decreased TNFα-induced oxidative stress in hepatocytes and reduced NF-kB activity in both cells. SRB1 silencing reduced TNFα gene expression in LPS-stimulated KCs, and NOX-1 and IL-6 in HepG2. Conclusions: Intestinal activation of LXRα modulates hepatic response to injury by increasing circulating HDL levels and SRB1 expression in the liver, thus suggesting this circuit as potential actionable pathway for therapy

HCC development is associated to peripheral insulin resistance in a mouse model of NASH

NAFLD is the most common liver disease worldwide but it is the potential evolution to NASH and eventually to hepatocellular carcinoma (HCC), even in the absence of cirrhosis, that makes NAFLD of such clinical importance. Aim: we aimed to create a mouse model reproducing the pathological spectrum of NAFLD and to investigate the role of possible co-factors in promoting HCC. Methods: mice were treated with a choline-deficient L-amino-acid-defined-diet (CDAA) or its control (CSAA diet) and subjected to a low-dose i.p. injection of CCl 4 or vehicle. Insulin resistance was measured by the euglycemic-hyperinsulinemic clamp method. Steatosis, fibrosis and HCC were evaluated by histological and molecular analysis. Results: CDAA-treated mice showed peripheral insulin resistance at 1 month. At 1-3 months, extensive steatosis and fibrosis were observed in CDAA and CDAA+CCl4 groups. At 6 months, equal increase in steatosis and fibrosis was observed between the two groups, together with the appearance of tumor. At 9 months of treatment, the 100% of CDAA+ CCl4 treated mice revealed tumor versus 40% of CDAA mice. Insulin-like Growth Factor-2 (IGF-2) and Osteopontin (SPP-1) were increased in CDAA mice versus CSAA. Furthermore, Immunostaining for p-AKT, p-c-Myc and Glypican-3 revealed increased positivity in the tumors. Conclusions: the CDAA model promotes the development of HCC from NAFLD-NASH in the presence of insulin resistance but in the absence of cirrhosis. Since this condition is increasingly recognized in humans, our study provides a model that may help understanding mechanisms of carcinogenesis in NAFLD. © 2014 De Minicis et al