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Both obesity and alcohol can cause oxidative stress, cytokine induction, and steatohepatitis. To determine the consequences of their combination, we compared the hepatic effects of moderate ethanol binges in lean and obese ob/ob mice. Mice received water or ethanol (2.5 g/kg) by gastric intubation daily for 4 days, and were killed 2 hours after the last administration. Some obese mice also received pentoxifylline, an inhibitor of tumor necrosis factor-␣ (TNF-␣) production, before each ethanol administration. In lean mice, these moderate ethanol doses did not increase plasma TNF-␣ and hepatic caspase-3 activity, but triggered some apoptotic hepatocytes. Naive ob/ob mice had a few necrotic and apoptotic hepatocytes, but exhibited little oxidative stress, possibly because of adaptive increases in manganese superoxide dismutase, heat shock protein 70 (Hsp70), mitochondrial cytochrome c, and mitochondrial DNA. Alcohol administration to ob/ob mice did not increase oxidative stress despite increased CYP2E1, but increased plasma TNF-␣, further increased Hsp70, and profoundly decreased p65 nuclear factor B (NF-B) protein and DNA-binding activity in nuclear extracts. Caspase-3 was activated, and more apoptotic hepatocytes were found in intoxicated obese mice than naive obese mice. In intoxicated obese mice, pentoxifylline fully prevented the increase in plasma TNF-␣ the decrease in nuclear NF-B activity, and the increase in hepatic caspase-3, and it also decreased hepatic triglycerides. In conclusion, obese mice develop adaptations that may limit oxidative stress. Moderate ethanol intoxication does not increase oxidative stress in obese mice, but increases TNF-␣ and also decreases nuclear NF-B activity, thus unleashing the apoptotic effects of TNF-␣. Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience.wiley.com/jpages/ 0270-9139/suppmat/index.html). (HEPATOLOGY 2005;42:1280-1290

Recent reports in patients with PFIC1 have indicated that a gene defect in ATP8B1 could cause deregulations in bile salt transporters through decreased expression and/or activity of FXR. This study aimed to: (1) define ATP8B1 expression in human hepatobiliary cell types, and (2) determine whether ATP8B1 defect affects gene expressions related to bile secretion in these cells. ATP8B1 expression was detected by RT-PCR in hepatocytes and cholangiocytes isolated from normal human liver and gallbladder. ATP8B1 mRNA levels were 20-and 200-fold higher in bile duct and gallbladder epithelial cells, respectively, than in hepatocytes. RT-PCR analyses of the liver from two patients with PFIC1, one with PFIC2, one with biliary atresia, showed that, compared to normal liver, hepatic expressions of FXR, SHP, CYP7A1, ASBT were decreased at least by 90% in all cholestatic disorders. In contrast, NTCP transcripts were less decreased (by <30% vs. 97%) in PFIC1 as compared with other cholestatic disorders, while BSEP transcripts, in agreement with BSEP immunohistochemical signals, were normal or less decreased (by 50% vs. 97%). CFTR hepatic expression was decreased (by 80%), exclusively in PFIC1, while bile duct mass was not reduced, as ascertained by cytokeratin-19 immunolabeling. In Mz-ChA-2 human biliary epithelial cells, a significant decrease in CFTR expression was associated with ATP8B1 invalidation by siRNA. In conclusion, cholangiocytes are a major site of ATP8B1 hepatobiliary expression. A defect of ATP8B1 along with CFTR downregulation can impair the contribution of these cells to bile secretion, and potentially explain the extrahepatic cystic fibrosis-like manifestations that occur in PFIC1. (HEPATOLOGY 2006;43:1125-1134 P rogressive familial intrahepatic cholestasis (PFIC) represents a heterogeneous group of inherited disorders, in which cholestasis starts in infancy and generally leads to liver failure in childhood. Three types of PFIC, caused by mutations in three separate genes, are currently recognized. The first two types, PFIC1 and 2, share common phenotypic features, including normal or nearly normal serum ␥-glutamyl transpeptidase activity and little bile duct proliferation, that are unusual in other types of cholestatic liver diseases. 1 In PFIC2, mutations affect the ABCB11 gene, which encodes a bile salt transporter, the canalicular bile salt export pump (BSEP). 2 Thus, a defect in the extrusion of bile salts across the canalicular membrane of hepatocytes is the primary cause of cholestasis in PFIC2. In PFIC1, mutations affect the ATP8B1 gene, which encodes a protein also called FIC1. 3 ATP8B1 protein belongs to a subfamily of P-type adenosine triphosphatases. Two members of this subfamily including ATP8B1 have been reported to mediate aminophospholipid translocation in plasma membranes. 4,5 The physiological function of ATP8B1 protein and the mechanisms by which ATP8B1 deficiency leads to PFIC1 disease remain poorly understood. It was previously shown that ATP8B1 is expressed in different tissues such as th...

The expansion of solid tumours is critically dependent on vascular networks resulting from angiogenesis that provide nutrients to support tumour growth. 1 In this tumoural angiogenic context, the provisionally endothelium extracellular matrix (ECM) of new capillary provide a permissive microenvironment enabling tumour cell anchorage and subsequent invasion. 1 In order for a tumour to grow and metastasise, neoplastic and endothelial cells must remodel ECM, migrate and invade into the surrounding tissues. 2 Thus, concerted and controlled expression of cell adhesion molecules and proteolytic enzymes seems to be required to promote tumour migration especially into endothelial environment.Cell adhesion to ECM is mainly mediated by integrins, a transmembrane receptors family, composed of 18 ␣ and 8 ␤ chains that combine to give 24 heterodimeric glycoproteins with distinct cellular and adhesive specificities. 2 Among them, ␣v integrins are receptors for a wide variety of ECM proteins including fibronectin (Fn) and vitronectin (Vn) and appear to be pivotal in tumour behaviour. Indeed, ␣v␤3 is strongly involved in tumour growth and invasion such as melanoma and breast cancer, 3,4 while engagement of this adhesive receptor during melanoma transendothelial migration has been recently reported. 5 Integrins are also involved in regulating activities of matrix metalloproteinases (MMPs), a family of zinc and calcium dependent enzymes. 2,6 MMPs mediate invasive properties of most malignant cells and promote angiogenesis through their ability to degrade basement membranes and to remodel ECM architecture. 6 -8 In particular, increasing expression of MMP2 by cancer cells is generally correlated with a poor prognosis. 7,8 Recent reports also showed that angiogenesis and corresponding tumour growth are reduced in MMP2 knock-out mice suggesting that MMP2 is a key player in neoangiogenesis. 7 MMP2 is secreted as an inactive zymogen that can be activated by MT1-MMP, a membrane bound MMPs, reported to be over expressed in several malignant tumour tissues. [7][8][9] Recent studies demonstrated that MMP2 activating complex also includes ␣v␤3 integrin. 9 Thus, MMP2-MT1MMP and ␣v␤3 integrin are functionally linked to activate MMP2, thereby localising its proteolytic activity to the invasive front of tumour cells 10 and to promote cancer cell locomotion. 9 Ovarian carcinoma, which arise from the malignant transformation of ovarian surface epithelium cells, 11 are associated with a poor prognosis and are diagnosed at advanced stages. Ovarian carcinoma are highly vascularised 12 and their expansion seems to be dependent upon their vascularisation. Some studies suggested that tumour angiogenesis is a prognostic factor in ovarian carcinoma, 12,13 while reports described the presence of ovarian metastasis localised in extraperitoneal sites like bone marrow and brain. 14,15 Taken together these data suggest the existence of a haematogenous way of dissemination for ovarian carcinoma. Nevertheless, cellular processes that lead to ovarian cancer cel...

BackgroundWhole rye (WR) consumption seems to be associated with beneficial health effects. Although rye fiber and polyphenols are thought to be bioactive, the mechanisms behind the health effects of WR have yet to be fully identified. This study in rats was designed to investigate whether WR can influence the metabolism of n-3 and n-6 long-chain fatty acids (LCFA) and gut microbiota composition.MethodsFor 12 weeks, rats were fed a diet containing either 50% WR or 50% refined rye (RR). The WR diet provided more fiber (+21%) and polyphenols (+29%) than the RR diet. Fat intake was the same in both diets and particularly involved similar amounts of essential (18-carbon) n-3 and n-6 LCFAs.ResultsThe WR diet significantly increased the 24-hour urinary excretion of polyphenol metabolites–including enterolactone–compared with the RR diet. The WR rats had significantly more n-3 LCFA–in particular, eicosapentanoic (EPA) and docosahexanoic (DHA) acids–in their plasma and liver. Compared with the RR diet, the WR diet brought significant changes in gut microbiota composition, with increased diversity in the feces (Shannon and Simpson indices), decreased Firmicutes/Bacteroidetes ratio and decreased proportions of uncultured Clostridiales cluster IA and Clostridium cluster IV in the feces. In contrast, no difference was found between groups with regards to cecum microbiota. The WR rats had lower concentrations of total short-chain fatty acids (SCFA) in cecum and feces (p<0.05). Finally, acetate was lower (p<0.001) in the cecum of WR rats while butyrate was lower (p<0.05) in the feces of WR rats.InterpretationThis study shows for the first time that WR consumption results in major biological modifications–increased plasma and liver n-3 EPA and DHA levels and improved gut microbiota profile, notably with increased diversity–known to provide health benefits. Unexpectedly, WR decreased SCFA levels in both cecum and feces. More studies are needed to understand the interactions between whole rye (fiber and polyphenols) and gut microbiota and also the mechanisms of action responsible for stimulating n-3 fatty acid metabolism.

Both acute and chronic alcohol consumption increase reactive oxygen species (ROS) formation and lipid peroxidation, whose products damage hepatic mitochondrial DNA (mtDNA). To test whether manganese superoxide dismutase (MnSOD) overexpression modulates acute and chronic alcohol-induced mtDNA lesions, transgenic MnSOD-overexpressing (TgMnSOD⁺⁺⁺) mice and wild-type (WT) mice were treated by alcohol, either chronically (7 weeks in drinking water) or acutely (single intragastric dose of 5 g/kg). Acute alcohol administration increased mitochondrial ROS formation, decreased mitochondrial glutathione, depleted and damaged mtDNA, durably increased inducible nitric oxide synthase (NOS) expression, plasma nitrites/nitrates and the nitration of tyrosine residues in complex V proteins and decreased complex V activity in WT mice. These effects were prevented in TgMnSOD⁺⁺⁺ mice. In acutely alcoholized WT mice, mtDNA depletion was prevented by tempol, a superoxide scavenger, L-NAME and 1400W, two NOS inhibitors, or uric acid, a peroxynitrite scavenger. In contrast, chronic alcohol consumption decreased cytosolic glutathione and increased hepatic iron, lipid peroxidation products and respiratory complex I protein carbonyls only in ethanol-treated TgMnSOD⁺⁺⁺ mice but not in WT mice. In chronic ethanol-fed TgMnSOD⁺⁺⁺ mice, but not WT mice, mtDNA was damaged and depleted, and the iron chelator, deferoxamine (DFO), prevented this effect. In conclusion, MnSOD overexpression prevents mtDNA depletion after an acute alcohol binge but aggravates this effect after prolonged alcohol consumption, which selectively triggers iron accumulation in TgMnSOD⁺⁺⁺ mice but not in WT mice. In the model of acute alcohol binge, the protective effects of MnSOD, tempol, NOS inhibitors and uric acid suggested a role of the superoxide anion reacting with NO to form mtDNA-damaging peroxynitrite. In the model of prolonged ethanol consumption, the protective effects of DFO suggested the role of iron reacting with hydrogen peroxide to form mtDNA-damaging hydroxyl radical.

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MethodsThese studies were designed to assess whether wheat polyphenols (mainly ferulic acid [FA]) increased the very-long-chain omega-3 fatty acids (VLC n-3) [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] in rats. Wheat aleurone (WA) was used as a dietary source of wheat polyphenols. Two experiments were performed; in the first one, the rats were fed WA or control pellets (CP) in presence of linseed oil (LO) to provide alpha-linolenic acid (ALA), the precursor of VLC n-3. In the second one, the rats were fed WA or CP in presence of control oil (CO) without ALA. The concentrations of phenolic acid metabolites in urine were also investigated.ResultsThe urinary concentration of conjugated FA increased with WA ingestion (p<0.05). Plasma EPA increased by 25% (p<0.05) with WA in the CO group but not in the LO group. In contrast, there was no effect of WA on plasma DHA and omega-6 fatty acids (n-6). Finally, both n-3 and n-6 in the liver remained unchanged by the WA.ConclusionThese results suggest that WA consumption has a significant effect on EPA in plasma without affecting n-6. Subsequent studies are required to examine whether these effects may explain partly the health benefits associated with whole wheat consumption.