Obesity: Kishimoto K

Moriyama T, Kishimoto K, Nagai K, Urade R, Ogawa T, Utsumi S, Maruyama N, Maebuchi M. · Graduate School of Agriculture, Kyoto University, Japan. · Biosci Biotechnol Biochem. · Pubmed #14981298 links to  free full text

Abstract: The purpose of this study was to discover the effects of soybean beta-conglycinin (7S-globulin) and glycinin (11S-globulin) on serum lipid levels and metabolism in the livers of normal and genetically obese mice. Male normal (ICR) and obese (KK-Ay) mice were fed ad libitum high fat diets for two weeks, followed by a 2-week restriction of diet (2 g diet/mouse/day) containing 20% casein, soybean beta-conglycinin, or soybean glycinin, and then sacrificed immediately. Serum triglyceride (TG), glucose, and insulin levels of beta-conglycinin-fed mice were lower than in casein- and glycinin-fed mice of both strains. In order to analyze the related events to these effects, enzyme activities and relative mRNA levels of lipid metabolism-related proteins were measured. The activities of two enzymes related to fatty acid beta-oxidation were higher while that of fatty acid synthase was lower in livers of beta-conglycinin-fed mice than of casein-fed both mice. Messenger RNA levels of acyl-CoA oxidase (fatty acid beta-oxidation related enzyme) were significantly higher in livers of beta-conglycinin-fed mice than of both casein-fed mice. On the contrary, mRNA levels of SREBP-1 and 2 tended to be lowered in livers of soy protein-fed mice than of both casein-fed mice. Fecal excretion of TG was higher in beta-conglycinin-fed mice than in casein-fed mice. Our results demonstrated that the soy beta-conglycinin diet reduced serum TG levels by acceleration of beta-oxidation, suppression of fatty acid synthase and/or increased TG fecal excretion, and also diminished serum glucose and insulin levels. Some of these events might be caused at the transcriptional levels, judged from the result that relative messenger RNA levels of lipid metabolism-related proteins were altered. These results suggest that soy beta-conglycinin could be a potentially useful dietary protein source for the prevention of hypertriglyceridemia, hyperinsulinemia, and hyperglycemia, which are recognized as risk factors for atherosclerosis.

Fukuhara A, Matsuda M, Nishizawa M, Segawa K, Tanaka M, Kishimoto K, Matsuki Y, Murakami M, Ichisaka T, Murakami H, Watanabe E, Takagi T, Akiyoshi M, Ohtsubo T, Kihara S, Yamashita S, Makishima M, Funahashi T, Yamanaka S, Hiramatsu R, Matsuzawa Y, Shimomura I. · Department of Medicine and Pathophysiology, Graduate School of Medicine, and Department of Organismal Biosystems, Graduate School of Frontier Biosciences, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan. · Science. · Pubmed #15604363 links to  free full text

Abstract: Fat tissue produces a variety of secreted proteins (adipocytokines) with important roles in metabolism. We isolated a newly identified adipocytokine, visfatin, that is highly enriched in the visceral fat of both humans and mice and whose expression level in plasma increases during the development of obesity. Visfatin corresponds to a protein identified previously as pre-B cell colony-enhancing factor (PBEF), a 52-kilodalton cytokine expressed in lymphocytes. Visfatin exerted insulin-mimetic effects in cultured cells and lowered plasma glucose levels in mice. Mice heterozygous for a targeted mutation in the visfatin gene had modestly higher levels of plasma glucose relative to wild-type littermates. Surprisingly, visfatin binds to and activates the insulin receptor. Further study of visfatin's physiological role may lead to new insights into glucose homeostasis and/or new therapies for metabolic disorders such as diabetes.