[Show abstract][Hide abstract] ABSTRACT: Various factors have been reported to influence lipid metabolism and cause metabolic syndrome. However, the influence of allergy on the liver that plays important role of lipid metabolism has not been clarified. The aim of this study was to examine the influence of allergy on lipid metabolism of liver. A model of atopic dermatitis was developed in the NC/Nga mouse using picryl chloride to induce allergy. Lipid metabolism parameters were measured and the mechanism of changes in these parameters was examined using DNA microarray analysis and quantitative reverse transcriptase PCR. Triacylglycerol accumulation was promoted in the liver in the mouse atopic dermatitis model despite reductions in food intake, body weight gain, and serum glucose. As this mechanism, it was thought that atopic dermatitis caused the suppression of fatty acid β-oxidation. These results suggest that atopic dermatitis causes lipid accumulation in the liver.
Full-text · Article · Mar 2012 · Journal of Clinical Biochemistry and Nutrition
[Show abstract][Hide abstract] ABSTRACT: Conjugated linoleic acid(CLA)comprises geometrical and positional isomers of linoleic acid and is a fatty acid with a conjugated double bond. The activities of CLA, including anti-obesity and anti-cancer activities, are known, and CLA is now used as a health-food supplement for its beneficial effects. However, there are few reported studies on CLA intake, absorption and metabolism in the Japanese population. Information about CLA intake in Japanese individuals was obtained in the present study by examining the daily intake of CLA, normal blood CLA levels, and the change in blood CLA levels after taking a CLA supplement. Results indicate that the normal dietary intake of CLA for Japanese individuals is 37.5 mg/day. Normal blood CLA levels are 6.4 μmol/L in plasma and 1.7 μmol/L in red blood cells. After taking 2.3 g/day of a CLA supplement for three weeks, blood CLA levels were 7.7-fold higher in plasma and 8.7-fold higher in red blood cells. Although normal dietary intake and blood levels of CLA in Japanese individuals were lower than those in non-Japanese subjects reported in previous studies, Japanese individuals taking a dietary supplement of CLA showed a dramatic increase in blood CLA levels. Therefore, long-term intake of 2.3 g CLA/day as a dietary supplement likely has a positive effect in Japanese individuals.
No preview · Article · Jan 2012 · Nippon Shokuhin Kagaku Kogaku Kaishi
[Show abstract][Hide abstract] ABSTRACT: Lipid metabolism in a child may be altered when the mother has a high-fat diet (HFD), but it is unclear whether the lipid metabolism of future offspring (grandchildren) is also changed under these circumstances. In this study, we examined the influence of intake of an HFD beyond one generation on offspring in normal mice. Parent mice fed an HFD were bred and the resultant second and third generations were also fed an HFD. The diets used in the study had approximately 20% more energy than a standard chow diet. Changes in lipid metabolism were examined in each generation. Intake of an HFD from generation to generation promoted lipid accumulation in the white adipose tissue of female mice, increased lipid, glucose and insulin levels in the serum, increased the activities of enzymes associated with fatty acid metabolism in the liver, promoted lipid accumulation in hepatocytes and adipocytes and increased the mRNA levels of Cdkn1a in the liver and white adipose tissue. These results suggest that activation of Cdkn1a promoted lipid accumulation in the liver and white adipose tissue of third-generation female mice that were offspring from earlier generations fed HFDs. Moreover, intake of a high-energy diet beyond one generation led to offspring with obesity, fatty liver and hyperinsulinemia.
No preview · Article · Jul 2011 · The Journal of nutritional biochemistry
[Show abstract][Hide abstract] ABSTRACT: We investigated whether replicative senescence of endothelial cells contributed to the pathogenesis of atherosclerosis in human umbilical vein endothelial cells (HUVECs). HUVECs at a population-doubling level of 30 (PDL30) divided much more slowly than those at PDL9. The percentage of SA-β-Gal-positive cells and the mRNA expression levels of PAI-1 and p21 at PDL30 were significantly higher than those at PDL9. The changes induced by aging were evaluated according to the mRNA expression level of genes related to the endothelial cell function. The expression level of many adhesion molecules promoting monocytic adhesion was significantly increased, and monocytic adhesion on HUVECs was found to be significantly promoted by aging. Monocytic adhesion is an essential early event in the development of atherosclerosis, and our results suggest that replicative senescence of the vascular endothelial cells induced increased expression of adhesion molecules. The consequent increase in monocytic adhesion may then promote the pathogenesis of atherosclerosis.
No preview · Article · Jun 2011 · Bioscience Biotechnology and Biochemistry
[Show abstract][Hide abstract] ABSTRACT: Conjugated linoleic acid (CLA) is a collective term used for fatty acids with a conjugated double bond that are geometrical and positional isomers of linoleic acid. Anti-obesity and anti-cancer properties, an immunopotentiation effect, and promotion of bone formation by CLA have been shown in cell culture and animal studies. A mixture of 9c11t- and 10t12c-CLA is now used as a health food supplement after testing in clinical trials. These trials focused on improvement of lipid metabolism by CLA, whereas few studies have examined absorption and metabolism of CLA in humans. In addition, there is no report concerning absorption and metabolism of CLA in Japanese. This study was designed to examine CLA concentration in blood, the elimination rate of CLA, and metabolic differences between 9c11t-CLA and 10t12c-CLA in blood in Japanese who ingested CLA (about 2 g/d, equal weights of 9c11t-CLA and 10t12c-CLA) for 3 wk. Blood samples were collected 1 wk before the 3-wk period, on the first and last days of the period, and 1 wk after the end of the period, and the CLA concentration and distribution in blood were investigated. The CLA concentration in blood was significantly increased by CLA ingestion and reached 36 µmol/L. The CLA concentration in blood one week after the intake period was significantly lower than that at the end of CLA intake. The 10t12c-CLA level in plasma decreased faster than that of 9c11t-CLA. This suggests faster metabolism (fatty acid β oxidation) of 10t12c-CLA compared with 9c11t-CLA.
No preview · Article · Feb 2011 · Journal of Nutritional Science and Vitaminology
[Show abstract][Hide abstract] ABSTRACT: Excessive trans-fatty acids (TFA) consumption has been thought to be a risk factor mainly for coronary artery diseases while less attention has been paid to liver disease. We aimed to clarify the impact of TFA-rich oil consumption on the hepatic pathophysiology compared to natural oil.
Mice were fed either a low-fat (LF) or high-fat (HF) diet made of either natural oil as control (LF-C or HF-C) or partially hydrogenated oil, TFA-rich oil (LF-T or HF-T) for 24 weeks. We evaluated the liver and body weight, serological features, liver lipid content and composition, liver histology and hepatic lipid metabolism-related gene expression profile. In addition, primary cultures of mice Kupffer cells (KCs) were evaluated for cytokine secretion and phagocytotic ability after incubation in cis- or trans-fatty acid-containing medium.
The HF-T-fed mice showed significant increases of the liver and body weights, plasma alanine-aminotransferase, free fatty acid and hepatic triglyceride content compared to the HF-C group, whereas the LF-T group did not differ from the LF-C group. HF-T-fed mice developed severe steatosis, along with increased lipogenic gene expression and hepatic TFA accumulation. KCs showed increased tumor necrosis factor secretion and attenuated phagocytotic ability in the TFA-containing medium compared to its cis-isomer.
Excessive consumption of the TFA-rich oil up-regulated the lipogenic gene expression along with marked hepatic lipid accumulation. TFA might be pathogenic through causing severe steatosis and modulating the function of KCs. The quantity and composition of dietary lipids could be responsible for the pathogenesis of non-alcoholic steatohepatitis.
No preview · Article · Apr 2010 · Journal of Hepatology