Impact of common risk factors of fibrosis progression in chronic hepatitis C.

OBJECTIVE: The natural course of chronic hepatitis C varies widely. To improve the profiling of patients at risk of developing advanced liver disease, we assessed the relative contribution of factors for liver fibrosis progression in hepatitis C. DESIGN: We analysed 1461 patients with chronic hepatitis C with an estimated date of infection and at least one liver biopsy. Risk factors for accelerated fibrosis progression rate (FPR), defined as ≥0.13 Metavir fibrosis units per year, were identified by logistic regression. Examined factors included age at infection, sex, route of infection, HCV genotype, body mass index (BMI), significant alcohol drinking (≥20 g/day for ≥5 years), HIV coinfection and diabetes. In a subgroup of 575 patients, we assessed the impact of single nucleotide polymorphisms previously associated with fibrosis progression in genome-wide association studies. Results were expressed as attributable fraction (AF) of risk for accelerated FPR. RESULTS: Age at infection (AF 28.7%), sex (AF 8.2%), route of infection (AF 16.5%) and HCV genotype (AF 7.9%) contributed to accelerated FPR in the Swiss Hepatitis C Cohort Study, whereas significant alcohol drinking, anti-HIV, diabetes and BMI did not. In genotyped patients, variants at rs9380516 (TULP1), rs738409 (PNPLA3), rs4374383 (MERTK) (AF 19.2%) and rs910049 (major histocompatibility complex region) significantly added to the risk of accelerated FPR. Results were replicated in three additional independent cohorts, and a meta-analysis confirmed the role of age at infection, sex, route of infection, HCV genotype, rs738409, rs4374383 and rs910049 in accelerating FPR. CONCLUSIONS: Most factors accelerating liver fibrosis progression in chronic hepatitis C are unmodifiable.

Endocrine causes of nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the industrialized world. The prevalence of NAFLD is increasing, becoming a substantial public health burden. NAFLD includes a broad spectrum of disorders, from simple conditions such as steatosis to severe manifestations such as fibrosis and cirrhosis. The relationship of NAFLD with metabolic alterations such as type 2 diabetes is well described and related to insulin resistance, with NAFLD being recognized as the hepatic manifestation of metabolic syndrome. However, NAFLD may also coincide with endocrine diseases such as polycystic ovary syndrome, hypothyroidism, growth hormone deficiency or hypercortisolism. It is therefore essential to remember, when discovering altered liver enzymes or hepatic steatosis on radiological exams, that endocrine diseases can cause NAFLD. Indeed, the overall prognosis of NAFLD may be modified by treatment of the underlying endocrine pathology. In this review, we will discuss endocrine diseases that can cause NALFD. Underlying pathophysiological mechanisms will be presented and specific treatments will be reviewed.

Outcomes After Liver Resection for Hepatic Alveolar Echinococcosis: A Single-Center Cohort Study.

BACKGROUND: Switzerland is a region in which alveolar echinococcosis (AE) is endemic. Studies evaluating outcomes after liver resection (LR) for AE are scarce. The aim of this study was to assess the short- and long-term outcomes of AE patients after LR in a single tertiary referral center. METHODS: We retrospectively analyzed data pertaining to all patients with liver AE who were treated with LR at our institution between January 1992 and December 2013. Patient demographics, intraoperative data, extent of LR procedures (major vs. minor LR), postoperative outcomes, and negative histological margin (R0) resection rate were recorded in a database. Recurrence rates after LR were analyzed. RESULTS: LR was performed in 59 patients diagnosed with hepatic AE (56 complete surgeries, 3 reduction surgeries). Postoperative morbidity and mortality were observed in 34 % (25 % grade I-II, 9 % grade III-IV) and 2 % of the patients, respectively. R0 (complete) resection rate was 71 % (n = 42), and R1/R2 resection rate was 29 % (n = 17). Extra-hepatic recurrence occurred in 1 case (lung) after R0 resection. In cases of R1/R2 resection, 7 intra-hepatic disease progressions occurred with a median time of 10 months (IQR 6-11 months). Long-term (more than 1 year) benzimidazole treatment stabilized the disease in 64 % (9/14) of patients with R1 status. The overall survival rate was 97 %. CONCLUSIONS: Liver AE can be safely and definitively treated with LR, provided that R0 resection is achieved. In cases of R1 resection, benzimidazole therapy seems to be effective in stabilizing the intra-hepatic disease and preventing extra-hepatic recurrence.

B cell activating factor is central to bleomycin- and IL-17-mediated experimental pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive devastating, yet untreatable fibrotic disease of unknown origin. We investigated the contribution of the B-cell activating factor (BAFF), a TNF family member recently implicated in the regulation of pathogenic IL-17-producing cells in autoimmune diseases. The contribution of BAFF was assessed in a murine model of lung fibrosis induced by airway administered bleomycin. We show that murine BAFF levels were strongly increased in the bronchoalveolar space and lungs after bleomycin exposure. We identified Gr1(+) neutrophils as an important source of BAFF upon BLM-induced lung inflammation and fibrosis. Genetic ablation of BAFF or BAFF neutralization by a soluble receptor significantly attenuated pulmonary fibrosis and IL-1β levels. We further demonstrate that bleomycin-induced BAFF expression and lung fibrosis were IL-1β and IL-17A dependent. BAFF was required for rIL-17A-induced lung fibrosis and augmented IL-17A production by CD3(+) T cells from murine fibrotic lungs ex vivo. Finally we report elevated levels of BAFF in bronchoalveolar lavages from IPF patients. Our data therefore support a role for BAFF in the establishment of pulmonary fibrosis and a crosstalk between IL-1β, BAFF and IL-17A.

PPARα is Required for PPARδ action in regulation of body weight and hepatic steatosis in mice.

NlmCategory="UNASSIGNED">Peroxisome proliferator activated receptors alpha (PPARα) and delta (PPARδ) belong to the nuclear receptor superfamily. PPARα is a target of well established lipid-lowering drugs. PPARδ (also known as PPARβ/δ) has been investigated as a promising antidiabetic drug target; however, the evidence in the literature on PPARδ effect on hepatic lipid metabolism is inconsistent. Mice conditionally expressing human PPARδ demonstrated pronounced weight loss and promoted hepatic steatosis when treated with GW501516 (PPARδ-agonist) when compared to wild type mice. This effect was completely absent in mice with either a dominant negative form of PPARδ or deletion of the DNA binding domain of PPARδ. This confirmed the absolute requirement for PPARδ in the physiological actions of GW501516 and confirmed the potential utility against the human form of this receptor. Surprisingly the genetic deletion of PPARα also abrogated the effect of GW501516 in terms of both weight loss and hepatic lipid accumulation. Also the levels of the PPARα endogenous agonist 16:0/18:1-GPC were shown to be modulated by PPARδ in wild type mice. Our results show that both PPARδ and PPARα receptors are essential for GW501516-driven adipose tissue reduction and subsequently hepatic steatosis, with PPARα working downstream of PPARδ.

Cell fusion reprogramming leads to a specific hepatic expression pattern during mouse bone marrow derived hepatocyte formation In Vivo

The fusion of bone marrow (BM) hematopoietic cells with hepatocytes to generate BM derived hepatocytes (BMDH) is a natural process, which is enhanced in damaged tissues. However, the reprogramming needed to generate BMDH and the identity of the resultant cells is essentially unknown. In a mouse model of chronic liver damage, here we identify a modification in the chromatin structure of the hematopoietic nucleus during BMDH formation, accompanied by the loss of the key hematopoietic transcription factor PU.1/Sfpi1 (SFFV proviral integration 1) and gain of the key hepatic transcriptional regulator HNF-1A homeobox A (HNF-1A/Hnf1a). Through genome-wide expression analysis of laser captured BMDH, a differential gene expression pattern was detected and the chromatin changes observed were confirmed at the level of chromatin regulator genes. Similarly, Tranforming Growth Factor-β1 (TGF-β1) and neurotransmitter (e.g. Prostaglandin E Receptor 4 [Ptger4]) pathway genes were over-expressed. In summary, in vivo BMDH generation is a process in which the hematopoietic cell nucleus changes its identity and acquires hepatic features. These BMDHs have their own cell identity characterized by an expression pattern different from hematopoietic cells or hepatocytes. The role of these BMDHs in the liver requires further investigation.

Efficacy of an eradication schema in case of Pseudomonas aeruginosa primo-infection in children with cystic fibrosis

Introduction: Patients with Cystic fibrosis (CF) are more susceptible to pathogens like P. aeruginosa (PA). PA primo-infection requires particular attention as failure in eradication is associated with accelerated lung deterioration. The main aim of this study is to assess the rate of PA eradication according to our particular protocol with inhaled tobramycin and oral ciprofloxacin, as there is no consensus in the literature on what eradication protocol is optimal. Methods: Retrospective single centre study with data analysis from June 1st 2007 to June 1st 2011 of patients with PA primo-infection exclusively treated by 3 x 28 days of inhaled tobramycin and oral ciprofloxacin for the first and last 21 days. Success in eradication is defined by ≥ 3 negative bacteriologies for 6 months after the beginning of the protocol. If ≥ 1 bacteriology is positive, we consider the eradication as a failure. Results: Out of 41 patients, 18 followed the eradication protocol and were included in our analysis (7 girls (38.9%) and 11 boys (61.1%)). Boys had 12 primo-infections and girls had 8. Among these 20 primo-infections, 16 (80%) had an overall success in eradication and 4 (20%) a failure. There was no significant statistical differences in age between these groups (t-test = 0.07, p = 0.94), nor for FEV1% (t-test = 0.96, p = 0.41) or BMI (t-test = 1.35, p = 0.27). Rate of success was 100% for girls and 66.6% for boys. Conclusion: Our protocol succeeded in an overall eradication rate of 80%, without statistical significant impact on FEV1 % and BMI values. However, there was a sex difference with eradication rates in girls (100%) and boys (66.6%). A sex difference has not yet been reported in the literature. This should be evaluated in further studies.

E2F1 mediates sustained lipogenesis and contributes to hepatic steatosis.

E2F transcription factors are known regulators of the cell cycle, proliferation, apoptosis, and differentiation. Here, we reveal that E2F1 plays an essential role in liver physiopathology through the regulation of glycolysis and lipogenesis. We demonstrate that E2F1 deficiency leads to a decrease in glycolysis and de novo synthesis of fatty acids in hepatocytes. We further demonstrate that E2F1 directly binds to the promoters of key lipogenic genes, including Fasn, but does not bind directly to genes encoding glycolysis pathway components, suggesting an indirect effect. In murine models, E2F1 expression and activity increased in response to feeding and upon insulin stimulation through canonical activation of the CDK4/pRB pathway. Moreover, E2F1 expression was increased in liver biopsies from obese, glucose-intolerant humans compared with biopsies from lean subjects. Finally, E2f1 deletion completely abrogated hepatic steatosis in different murine models of nonalcoholic fatty liver disease (NAFLD). In conclusion, our data demonstrate that E2F1 regulates lipid synthesis and glycolysis and thus contributes to the development of liver pathology.

Hepatic circadian clock oscillators and nuclear receptors integrate microbiome-derived signals.

The liver is a key organ of metabolic homeostasis with functions that oscillate in response to food intake. Although liver and gut microbiome crosstalk has been reported, microbiome-mediated effects on peripheral circadian clocks and their output genes are less well known. Here, we report that germ-free (GF) mice display altered daily oscillation of clock gene expression with a concomitant change in the expression of clock output regulators. Mice exposed to microbes typically exhibit characterized activities of nuclear receptors, some of which (PPARα, LXRβ) regulate specific liver gene expression networks, but these activities are profoundly changed in GF mice. These alterations in microbiome-sensitive gene expression patterns are associated with daily alterations in lipid, glucose, and xenobiotic metabolism, protein turnover, and redox balance, as revealed by hepatic metabolome analyses. Moreover, at the systemic level, daily changes in the abundance of biomarkers such as HDL cholesterol, free fatty acids, FGF21, bilirubin, and lactate depend on the microbiome. Altogether, our results indicate that the microbiome is required for integration of liver clock oscillations that tune output activators and their effectors, thereby regulating metabolic gene expression for optimal liver function.

Hepatic circadian clock oscillators and nuclear receptors integrate microbiome-derived signals.

The liver is a key organ of metabolic homeostasis with functions that oscillate in response to food intake. Although liver and gut microbiome crosstalk has been reported, microbiome-mediated effects on peripheral circadian clocks and their output genes are less well known. Here, we report that germ-free (GF) mice display altered daily oscillation of clock gene expression with a concomitant change in the expression of clock output regulators. Mice exposed to microbes typically exhibit characterized activities of nuclear receptors, some of which (PPARα, LXRβ) regulate specific liver gene expression networks, but these activities are profoundly changed in GF mice. These alterations in microbiome-sensitive gene expression patterns are associated with daily alterations in lipid, glucose, and xenobiotic metabolism, protein turnover, and redox balance, as revealed by hepatic metabolome analyses. Moreover, at the systemic level, daily changes in the abundance of biomarkers such as HDL cholesterol, free fatty acids, FGF21, bilirubin, and lactate depend on the microbiome. Altogether, our results indicate that the microbiome is required for integration of liver clock oscillations that tune output activators and their effectors, thereby regulating metabolic gene expression for optimal liver function.