PPAR Gamma and Hepatic Stellate Cells

Activation of Hepatic stellate cells (HSC) in fibrogenesis involves distinct morphological and biochemical changes. This activation requires the coordinated changes in activity of several transcription factors. Peroxisome proliferator-activated receptor gamma (PPAR gamma) is one such factor whose activity is decreased in activated HSC. PPAR gamma ligands suppress several markers of HSC activation such as expression of collagen and alpha smooth muscle actin (alpha-SMA), cell proliferation and migration. Expression of PPAR gamma, per se, also inhibits HSC activation. These findings support the role of PPAR gamma in reversion of activated HSC toward their quiescent state

Pollock oil supplementation modulates hyperlipidemia and ameliorates hepatic steatosis in mice fed a high-fat diet

<p>Abstract</p> <p>Background</p> <p>Hyperlipidemia associated with obesity is closely related to the development of atherosclerosis. Both n-3 polyunsaturated fatty acids (PUFAs) and long-chain monounsaturated fatty acids (MUFAs; i.e., C20:1 and C22:1 isomers) supplementation modulate risk factors for metabolic syndrome via multiple mechanisms, including the restoration of impaired lipid metabolism. We therefore examined the effects of pollock oil, which contains a considerable amount of n-3 PUFAs as well as long-chain MUFAs, on plasma hyperlipidemia and hepatic steatosis in diet-induced obese mice.</p> <p>Methods</p> <p>Male C57BL/6J mice (24-26 g) were divided into two groups (n = 10/group) and were fed a high-fat diet containing 32% lard (control group) or 17% lard plus 15% pollock oil (experimental group) for 6 weeks. For both groups, fat comprised 60% of the total caloric intake.</p> <p>Results</p> <p>Although body and liver masses for the two groups did not differ significantly, hepatic lipids concentrations (triglycerides and total cholesterols) were lower (<it>P </it>< 0.05) after pollock oil ingestion. After 2 weeks on the specified diets, plasma lipid levels (total cholesterol, LDL cholesterol, and triglycerides) significantly decreased (<it>P </it>< 0.05) in the experimental group compared with the control group, although plasma HDL cholesterol levels did not differ. At the end of 6 weeks, plasma adiponectin levels increased (<it>P </it>< 0.05), whereas plasma resistin and leptin levels decreased (<it>P </it>< 0.05) in the experimental mice. Increased levels of long-chain MUFAs and n-3 PUFAs in plasma, liver and adipose tissue by ingesting pollock oil were possibly correlated to these favorable changes. Expression of hepatic genes involved in cholesterol metabolism (<it>SREBP2</it>, <it>HMGCR</it>, and <it>ApoB</it>) and lipogenesis (<it>SREPB1c</it>, <it>SCD-1</it>, <it>FAS</it>, and <it>Acac</it>α) was suppressed in the experimental group, and may have favorably affected hyperlipidemia and hepatic steatosis induced by the high-fat diet.</p> <p>Conclusions</p> <p>We demonstrated that pollock oil supplementation effectively improved hyperlipidemia, attenuated hepatic steatosis, and downregulated the express of hepatic genes involved in cholesterol and lipid metabolism in mice with diet-induced obesity.</p

Long-chain monounsaturated fatty acids improve endothelial function with altering microbial flora

Fish oil-derived long-chain monounsaturated fatty acids (LCMUFAs) with a carbon chain length longer than 18 units ameliorate cardiovascular risk in mice. In this study, we investigated whether LCMUFAs could improve endothelial functions in mice and humans. In a double-blind, randomized, placebo-controlled, parallel-group, multi-center study, healthy subjects were randomly assigned to either an LCMUFA oil (saury oil) or a control oil (olive and tuna oils) group. Sixty subjects were enrolled and administrated each oil for 4 weeks. For the animal study, ApoE−/− mice were fed a Western diet supplemented with 3% of either gadoleic acid (C20:1) or cetoleic acid (C22:1) for 12 weeks. Participants from the LCMUFA group showed improvements in endothelial function and a lower trimethylamine-N-oxide level, which is a predictor of coronary artery disease. C20:1 and C22:1 oils significantly improved atherosclerotic lesions and plasma levels of several inflammatory cytokines, including IL-6 and TNF-α. These beneficial effects were consistent with an improvement in the gut microbiota environment, as evident from the decreased ratio of Firmicutes and/ or Bacteroidetes, increase in the abundance of Akkermansia, and upregulation of short-chain fatty acid (SCFA)-induced glucagon-like peptide-1 (GLP-1) expression and serum GLP-1 level. These data suggest that LCMUFAs alter the microbiota environment that stimulate the production of SCFAs, resulting in the induction of GLP-1 secretion. Fish oil-derived long-chain monounsaturated fatty acids might thus help to protect against cardiovascular disease

RAPID HYDROGEN RANDOMIZATION IN AMMONIA

Short Not

Une histoire du Japon et de la Corée

Miyahara Takeo, Mollard Nicolas. Une histoire du Japon et de la Corée. In: Ebisu, n°38, 2007. pp. 13-21

Decreased accumulation of ultrasound contrast in the liver of nonalcoholic steatohepatitis rat model

AIM: To investigate the diagnosis of nonalcoholic steatohepatitis (NASH) using contrast ultrasonography in the NASH rat model