Stéphanie Patouraux

Hepatic expression patterns of inflammatory and immune response genes associated with obesity and NASH in morbidly obese patients.

Background Obesity modulates inflammation and activation of immune pathways which can lead to liver complications. We aimed at identifying expression patterns of inflammatory and immune response genes specifically associated with obesity and NASH in the liver of morbidly obese patients. Methodology/Principal Findings Expression of 222 genes was evaluated by quantitative RT-PCR in the liver of morbidly obese patients with histologically normal liver (n = 6), or with severe steatosis without (n = 6) or with NASH (n = 6), and in lean controls (n = 5). Hepatic expression of 58 out of 222 inflammatory and immune response genes was upregulated in NASH patients. The most notable changes occurred in genes encoding chemokines and chemokine receptors involved in leukocyte recruitment, CD and cytokines involved in the T cell activation towards a Th1 phenotype, and immune semaphorins. This regulation seems to be specific for the liver since visceral adipose tissue expression and serum levels of MCP1, IP10, TNFα and IL6 were not modified. Importantly, 47 other genes were already upregulated in histologically normal liver (e.g. CRP, Toll-like receptor (TLR) pathway). Interestingly, serum palmitate, known to activate the TLR pathway, was increased with steatosis. Conclusion/Significance The liver of obese patients without histological abnormalities already displayed a low-grade inflammation and could be more responsive to activators of the TLR pathway. NASH was then characterized by a specific gene signature. These findings help to identify new potential actors of the pathogenesis of NAFLD.

Regular coffee but not espresso drinking is protective against fibrosis in a cohort mainly composed of morbidly obese European women with NAFLD undergoing bariatric surgery

BACKGROUND & AIMS The aim of this study was to determine the influence of coffee and other caffeinated drinks on liver fibrosis of severely obese European patients. METHODS A specific questionnaire exploring various types of coffee (regular filtrated coffee and espresso), caffeinated drinks, and chocolate was filled in by 195 severely obese patients. All patients had liver biopsies that were analyzed according to the NASH Clinical Research Network Scoring System. Univariate and multivariate analyses of significant fibrosis were performed. RESULTS Caffeine came mainly from coffee-containing beverages (77.5%). Regular coffee and espresso were consumed in 30.8% and 50.2% of the patients, respectively. Regular coffee, espresso, and total caffeine consumption was similar between patients with and without NASH. While consumption of espresso, caffeinated soft drinks, and chocolate was similar among patients, with respect to the level of fibrosis, regular coffee consumption was lower in patients with significant fibrosis (F ≥2). According to logistic regression analysis, consumption of regular coffee was an independent protective factor for fibrosis (OR: 0.752 [0.578-0.980], p=0.035) in a model including level of AST (OR: 1.04 [1.004-1.076], p=0.029), presence of NASH (OR: 2.41 [1.007-5.782], p=0.048), presence of the metabolic syndrome (NS), and level of HOMA-IR (NS). Espresso, but not regular coffee consumption was higher in patients with lower HDL cholesterol level, higher triglyceride level, and the metabolic syndrome. CONCLUSIONS Consumption of regular coffee but not espresso is an independent protective factor for liver fibrosis in severely obese European patients.

The Osteopontin Level in Liver, Adipose Tissue and Serum Is Correlated with Fibrosis in Patients with Alcoholic Liver Disease

Background Osteopontin (OPN) plays an important role in the progression of chronic liver diseases. We aimed to quantify the liver, adipose tissue and serum levels of OPN in heavy alcohol drinkers and to compare them with the histological severity of hepatic inflammation and fibrosis. Methodology/Principal Findings OPN was evaluated in the serum of a retrospective and prospective group of 109 and 95 heavy alcohol drinkers, respectively, in the liver of 34 patients from the retrospective group, and in the liver and adipose tissue from an additional group of 38 heavy alcohol drinkers. Serum levels of OPN increased slightly with hepatic inflammation and progressively with the severity of hepatic fibrosis. Hepatic OPN expression correlated with hepatic inflammation, fibrosis, TGFβ expression, neutrophils accumulation and with the serum OPN level. Interestingly, adipose tissue OPN expression also correlated with hepatic fibrosis even after 7 days of alcohol abstinence. The elevated serum OPN level was an independent risk factor in estimating significant (F≥2) fibrosis in a model combining alkaline phosphatase, albumin, hemoglobin, OPN and FibroMeter® levels. OPN had an area under the receiving operator curve that estimated significant fibrosis of 0.89 and 0.88 in the retrospective and prospective groups, respectively. OPN, Hyaluronate (AUROC: 0.88), total Cytokeratin 18 (AUROC: 0.83) and FibroMeter® (AUROC: 0.90) estimated significance to the same extent in the retrospective group. Finally, the serum OPN levels also correlated with hepatic fibrosis and estimated significant (F≥2) fibrosis in 86 patients with chronic hepatitis C, which suggested that its elevated level could be a general response to chronic liver injury. Conclusion/Significance OPN increased in the liver, adipose tissue and serum with liver fibrosis in alcoholic patients. Further, OPN is a new relevant biomarker for significant liver fibrosis. OPN could thus be an important actor in the pathogenesis of this chronic liver disease.

Serum Markers of Hepatocyte Death and Apoptosis Are Non Invasive Biomarkers of Severe Fibrosis in Patients with Alcoholic Liver Disease

Background Quantification of hepatotocyte death is useful to evaluate the progression of alcoholic liver diseases. Our aims were to quantify and correlate the circulating levels of Cytokeratin 18 (CK18) and its caspases-generated fragment to disease severity in heavy alcoholics. Methodology/Principal Findings CK18 and CK18-fragment were evaluated in the serum of 143 heavy alcoholics. Serum levels of markers of hepatocyte death (CK18), apoptosis (CK18 fragment) and necrosis (CK18 -CK18 fragment) increased in patients with severe fibrosis compared to patients with mild fibrosis. These markers strongly correlated with Mallory-Denk bodies, hepatocyte ballooning, fibrosis and with hepatic TNFα and TGFβ assessed in the liver of 24 patients. Elevated levels of serum hepatocyte death and apoptotic markers were independent risk factors in predicting severe fibrosis in a model combining alkaline phosphatase, bilirubin, prothrombin index, hyaluronate, hepatocyte death and apoptotic markers. The level of markers of hepatocyte death and apoptosis had an area under the receiving operator curve that predicted severe fibrosis of 0.84 and 0.76, respectively. Conclusion/Significance Death of hepatocytes can be easily evaluated with serum markers and correlated with severe fibrosis in heavy alcohol drinkers. These biomarkers could be useful to rapidly evaluate liver injuries and the efficacy of therapies.

Postnatal Soluble FGFR3 Therapy Rescues Achondroplasia Symptoms and Restores Bone Growth in Mice

A recombinant soluble fibroblast growth factor receptor 3 (FGFR3) restored normal skeletal growth and prevented disease-related complications in a mouse model of achondroplasia. Receptor Decoy Restores Bone Growth Achondroplasia is a rare disease where bone growth is stunted and cartilage does not form correctly. It is caused by a mutation in the gene that encodes fibroblast growth factor receptor 3 (FGFR3), which leads to overactive receptor signaling. Yet, despite knowing the cause, a treatment has not been discovered. In an innovative approach, Garcia and colleagues used receptor “decoys” to prevent the FGF ligand from binding its mutated receptor, thus interrupting the signaling cascade and restoring bone growth in mice. Normal mice or mice with the mutation in the gene encoding FGFR (Fgfr3ach/+) were treated with recombinant, soluble FGFR3 (sFGFR3) or a vehicle control for 3 weeks. More than 60% of Fgfr3ach/+ mice that were left untreated died during the treatment period, whereas only 12% of sFGFR3-treated mice died from achondroplasia-related complications, such as respiratory distress or paraplegia. In the surviving Fgfr3ach/+ animals, those treated with sFGFR3 had normal body and tail lengths, normal rib cage development, and decreased spinal and skull deformities—all similar to their healthy, wild-type counterparts. Untreated transgenic animals suffered from the defects common to achondroplasia: shortened stature, abnormal rib cage structure, and spinal compression, leading to paraplegia and bladder dysfunction. The sFGFR3 therapy was not toxic to the animals and did not affect reproduction (in fact, by increasing pelvis size in treated transgenic females, litter sizes were normal). Additional preclinical studies will be needed to see if this is a viable long-term treatment for achondroplasia, but with a long half-life and promising early outcomes in animals, this FGFR decoy may be a viable postnatal treatment for translation. Achondroplasia is a rare genetic disease characterized by abnormal bone development, resulting in short stature. It is caused by a single point mutation in the gene coding for fibroblast growth factor receptor 3 (FGFR3), which leads to prolonged activation upon ligand binding. To prevent excessive intracellular signaling and rescue the symptoms of achondroplasia, we have developed a recombinant protein therapeutic approach using a soluble form of human FGFR3 (sFGFR3), which acts as a decoy receptor and prevents FGF from binding to mutant FGFR3. sFGFR3 was injected subcutaneously to newborn Fgfr3ach/+ mice—the mouse model of achondroplasia—twice per week throughout the growth period during 3 weeks. Effective maturation of growth plate chondrocytes was restored in bones of treated mice, with a dose-dependent enhancement of skeletal growth in Fgfr3ach/+ mice. This resulted in normal stature and a significant decrease in mortality and associated complications, without any evidence of toxicity. These results describe a new approach for restoring bone growth and suggest that sFGFR3 could be a potential therapy for children with achondroplasia and related disorders.

Osteopontin deficiency aggravates hepatic injury induced by ischemia–reperfusion in mice

Osteopontin (OPN) is a multifunctional protein involved in hepatic steatosis, inflammation, fibrosis and cancer progression. However, its role in hepatic injury induced by ischemia–reperfusion (I–R) has not yet been investigated. We show here that hepatic warm ischemia for 45 min followed by reperfusion for 4 h induced the upregulation of the hepatic and systemic level of OPN in mice. Plasma aspartate aminotransferase and alanine aminotransferase levels were strongly increased in Opn−/− mice compared with wild-type (Wt) mice after I–R, and histological analysis of the liver revealed a significantly higher incidence of necrosis of hepatocytes. In addition, the expression levels of inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNFα), interleukin 6 (IL6) and interferon-γ were strongly upregulated in Opn−/− mice versus Wt mice after I–R. One explanation for these responses could be the vulnerability of the OPN-deficient hepatocyte. Indeed, the downregulation of OPN in primary and AML12 hepatocytes decreased cell viability in the basal state and sensitized AML12 hepatocytes to cell death induced by oxygen–glucose deprivation and TNFα. Further, the downregulation of OPN in AML12 hepatocytes caused a strong decrease in the expression of anti-apoptotic Bcl2 and in the ATP level. The hepatic expression of Bcl2 also decreased in Opn−/− mice versus Wt mice livers after I–R. Another explanation could be the regulation of the macrophage activity by OPN. In RAW macrophages, the downregulation of OPN enhanced iNOS expression in the basal state and sensitized macrophages to inflammatory signals, as evaluated by the upregulation of iNOS, TNFα and IL6 in response to lipopolysaccharide. In conclusion, OPN partially protects from hepatic injury and inflammation induced in this experimental model of liver I–R. This could be due to its ability to partially prevent death of hepatocytes and to limit the production of toxic iNOS-derived NO by macrophages.

Study of LAT1 Expression in Brain Metastases: Towards a Better Understanding of the Results of Positron Emission Tomography Using Amino Acid Tracers.

Positron emission tomography using radiolabeled amino acid (PET-AA) appears to be promising in distinguishing between recurrent tumour and radionecrosis in the follow-up of brain metastasis (BM). The amino acid transporter LAT1 and its cofactor CD98, which are involved in AA uptake, have never been investigated in BM. The aim of our study was to determine and compare the expression of LAT1 and CD98 in BM and in non-tumoral brain tissue (NT). The expression of LAT1 and CD98 were studied by immunohistochemistry in 67 BM, including 18 BM recurrences after radiotherapy, in 53 NT, and in 13 cases of patients with previously irradiated brain tumor and investigated by [18F] FDOPA-PET. LAT1 and CD98 expression were detected in 98.5% and 59.7% of BM respectively and were significantly associated with BM tissue as compared to NT (p<0.001). LAT1 expression in recurrent BM was significantly increased as compared to newly occurring BM. Ten cases investigated by [18F] FDOPA-PET corresponding to recurrent BM displayed significant [18F] FDOPA uptake and LAT1 overexpression whereas three cases corresponding to radionecrosis showed no or low uptake and LAT1 expression. LAT1 expression level and [18F] FDOPA uptake were significantly correlated. In conclusion, we hypothesized that BM may overexpress the AA transporter LAT1. We have shown that LAT1 overexpression was common in BM and was specific for BM as compared to healthy brain. These results could explain the specific BM uptake on PET-AA.

Roux-En Y Gastric Bypass Results in Long-Term Remission of Hepatocyte Apoptosis and Hepatic Histological Features of Non-alcoholic Steatohepatitis

The long-term effects of bariatric surgery on non-alcoholic steatohepatitis (NASH), focusing on liver injury and hepatocyte apoptosis, are not well-established. We here performed a longitudinal study with paired liver biopsies of nine morbidly obese women (median BMI: 42 [38.7; 45.1] kg/m2) with NASH with a median follow-up of 55 [44; 75] months after laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery. LRYGB surgery was associated with significant weight loss (median BMI loss −13.7 [−16.4; −9.5] kg/m2), improved hepatic steatosis in all patients (55.5% with total resolution), and resolution of hepatic inflammation and hepatocyte ballooning in 100 and 88.8% of cases, respectively. Alanine aminotransferase levels dropped to normal values while hepatic activated cleaved caspase-3 levels strongly decreased after a median follow-up of 55 months. Hepatocyte apoptosis, as evaluated by serum caspase-generated keratin-18 fragment, improved within the first year following LRYGB and these improvements persisted for at least 55 months. LRYGB in morbidly obese patients with NASH is thus associated with a long-lasting beneficial impact on hepatic steatohepatitis and hepatocyte death.

Severe Vitamin D Deficiency May be an Additional Cofactor for the Occurrence of Alcoholic Steatohepatitis

BACKGROUND Among its pleiotropic effects, vitamin D may protect the liver from fibrosis and/or inflammation. However, the impact of vitamin D on liver pathology in hepatitis C remains unclear, and very few studies including alcoholic patients with liver pathologies have been performed. Here we compared the levels of 25-OH vitamin D in the blood of alcoholic patients with the occurrence of alcoholic steatohepatitis (ASH) or bridging fibrosis. METHODS One hundred and one alcoholic patients were included. All the patients received a liver biopsy, and the levels of 25-OH vitamin D were evaluated with the Liaison 25-OH vitamin D assay. Logistic regression analyses were performed to obtain predictive factors of liver histology. RESULTS Among alcoholic patients, 40.6% presented ASH and 39.6% presented bridging fibrosis. A severe deficiency in 25-OH vitamin D (<10 ng/ml) was seen in 60.4% of patients. This deficiency was frequent in patients with ASH (85.4%) and in those with bridging fibrosis (80%) but was independently associated only with ASH (odds ratio = 8.46 [95% confidence interval 2.05 to 34.89], p = 0.003). CONCLUSIONS In alcoholic patients, a severe deficiency in 25-OH vitamin D was independently associated with the occurrence of ASH.

Hepatitis E: are rheumatic patients at risk?

To the Editor: Hepatitis E virus (HEV) is a major cause of acute hepatitis in developing countries, but remains infrequent in industrialized countries despite a growing number of cases1. It is a zoonosis related to domestic and also wild animals. In epidemic conditions HEV is transmitted mainly by drinking fecal-contaminated water, but it can also be transmitted person to person, or mother to fetus, and even through contaminated transfusions. Sporadic hepatitis E seems to be the most common manifestation in industrialized countries2. In France, genotype 3 is the most common. HEV infection is usually self-limited, symptomatic or asymptomatic, with possible acute hepatitis. Fulminant hepatitis may be observed in pregnant women and patients with underlying liver disease. Chronic infections can be detected in patients with transplants, lymphoma, leukemia with reactivation, in immunocompromised children, and in patients infected with human immunodeficiency virus. We describe a patient with rheumatoid arthritis (RA), treated with rituximab (RTX) and methotrexate (MTX), … Address correspondence to Dr. Roux; E-mail: roux101fr{at}yahoo.fr