Soy β-conglycinin improves glucose uptake in skeletal muscle and ameliorates hepatic insulin resistance in Goto-Kakizaki rats

Although the underlying mechanism is unclear, β-conglycinin (βCG), the major component of soy proteins, regulates blood glucose levels. Here, we hypothesized that consumption of βCG would normalize blood glucose levels by ameliorating insulin resistance and stimulating glucose uptake in skeletal muscles. To test our hypothesis, we investigated the antidiabetic action of βCG in spontaneously diabetic Goto-Kakizaki (GK) rats. Our results revealed that plasma adiponectin levels and adiponectin receptor 1 messenger RNA expression in skeletal muscle were higher in βCG-fed rats than in casein-fed rats. Phosphorylation of adenosine monophosphate–activated protein kinase (AMP kinase) but not phosphatidylinositol-3 kinase was activated in βCG-fed GK rats. Subsequently, βCG increased translocation of glucose transporter 4 to the plasma membrane. Unlike the results in skeletal muscle, the increase in adiponectin receptor 1 did not lead to AMP kinase activation in the liver of βCG-fed rats. The down-regulation of sterol regulatory element-binding factor 1, which is induced by low insulin levels, promoted the increase in hepatic insulin receptor substrate 2 expression. Based on these findings, we concluded that consumption of soy βCG improves glucose uptake in skeletal muscle via AMP kinase activation and ameliorates hepatic insulin resistance and that these actions may help normalize blood glucose levels in GK rats.     

Increased muscular triglyceride content and hyperglycemia in Goto-Kakizaki rat are decreased by egg white hydrolysate

We investigated the fat metabolic characteristics in non-obese and diabetic Goto-Kakizaki (GK) rat and the effects of dietary egg white hydrolysate (EWH) on glucose and fat metabolism. Wistar (W) and GK (G) rats were placed into dietary casein (WC and GC) or EWH (WE and GE) group, and fed their respective diet for six weeks. Triglyceride (TG) content and stearoyl-CoA desaturase (SCD) indices in the soleus muscle were higher in the GC group than WC group in parallel with worsening serum glucose metabolic parameters. The glucose metabolic parameters were significantly improved in the GE group. The TG accumulation and SCD indices in the soleus muscle were also significantly lower in the GE group than in the GC group. In conclusion, dietary EWH not only improved glucose metabolism but also reduced both TG accumulation and SCD indices in the soleus muscle of GK rat.     

Association of FADS2 rs174575 gene polymorphism and insulin resistance in type 2 diabetes mellitus

BackgroundMany risk factors contribute to the pathogenesis of diabetes. Gene and lifestyle factors are considered to be the major contributors. A dietary pattern is attributed to be one of the lifestyle risk factors favoring diabetes. The present study aims to find an association between fatty acid desaturase (FADS) gene polymorphism and glycemic profile in type 2 diabetes mellitus (T2DM).MethodologyA total of 429 subjects were included in the study on the basis of inclusion and exclusion criteria, of which 213 and 216 subjects were diabetic and control, respectively. Body mass index was calculated. Fasting plasma glucose, glycated hemoglobin (HbA1c) and insulin were measured using commercially available kits. rs174575 of FADS2 was selected based on previous publications and identified using the dbSNP database. To compare the biochemical parameters with the genotype, the following three models were used: additive model (CC vs CG vs GG), dominant model (CC + CG vs GG), and recessive model (CC vs CG + GG).Results and DiscussionFBS, HbA1c, insulin, HOMA-IR, and HOMA-B exhibited a high and statistically significant difference between subjects and controls. The three models exhibited a statistically significant difference between FBS, HOMA-IR, and HOMA- B (p<0.05).ConclusionThe distribution of rs174575 genotype differed significantly between the subjects and controls in the present study. The study revealed that genetic variation in FADS2 is an additional facet to consider while studying the risk factors of T2DM.     

多不饱和脂肪酸代谢与动脉粥样硬化的关系

动脉粥样硬化是多因素共同作用引起的,其发病机制复杂,目前尚未完全阐明。多不饱和脂肪酸作为脂肪酸家族中的一员,是哺乳动物生长发育的关键营养物质,其摄入种类和摄入量以及脂肪酸去饱和酶均能影响动脉粥样硬化性疾病的进程。脂肪酸去饱和酶基因簇能够调控脂肪酸去饱和酶的活性并进一步影响动脉粥样硬化。基于代谢和遗传学的观点,本文综述了多不饱和脂肪酸在脂肪酸去饱和酶的调节下对动脉粥样硬化影响的研究进展,并总结了脂肪酸去饱和酶基因簇变异与动脉粥样硬化性心血管疾病之间的关系。     

Polyunsaturated fatty acids are involved in regulatory mechanism of fatty acid homeostasis via daf-2/insulin signaling in Caenorhabditis elegans

The development of the dauer form of Caenorhabditis elegans daf-2(e1370) enhances the expression of genes such as fatty acid desaturase fat-6 and fat-7 and fatty acid elongase elo-2, and increases the level of triglyceride (TAG). RNA interference (RNAi) of the fat-6, fat-7, and elo-2 genes lowers fat accumulation in the nematode. We recently clarified the fact that RNAi of fat-related genes, especially fat-2, reduced fat accumulation and activated DAF-16.     

Characteristics of obese children with low content of arachidonic acid in plasma lipids

BACKGROUND: Although there have been many studies on the relationship between obesity and long-chain polyunsaturated fatty acid (LCPUFA), the results and their interpretation are controversial, especially in children. Arachidonic acid (AA), the product of n-6 LCPUFA, is reported to be related to insulin resistance. The purpose of the present paper was to investigate the LCPUFA profile in obese children and mechanisms that contribute to reduced AA content. METHOD: An age- and sex-matched control study was performed. The study subjects were 59 obese children (mean age, 11.8 years) and 53 healthy non-obese children (mean age, 12.5 years). The study parameters included anthropometric measurements, serum lipids, leptin and fatty acid composition in plasma. RESULTS: Plasma fatty acids in obese children had lower linoleic acid (P < 0.0001) and higher dihomo-gamma-linolenic acid (P = 0.0004) than those in non-obese children. In all subjects combined, delta-6 desaturase (D6D) index (ratios of [C 18:3n-6+C 20:2n-6]/C 20:4n-6 or C 20:4n-6/C 18: 2n-6) correlated with leptin (P < 0.0001). There was no significant difference in AA content between obese and non-obese. However, the AA content was low (相似文献   

The SAMP8 mouse: a model of Alzheimer disease?

The SAMP8 mice develops early abnormalities in learning and memory. These are related to abnormalities in septo-hippocampal function with a decrease in serotonin leading to an increase in GABA and a decrease in acetylcholine. The cognitive defects in these animals are due to overproduction of β-amyloidand can be reversed by antibodies toβ-amyloid or specific antisenseoligo nucleotides. The major defect produced byβ-amyloid in these mice appears to be reduction in Δ⁹ desaturase activity leading to altered membrane phospholipid content. The SAMP8 mouse appears to be an excellent model to examine the pathophysiology of early defects seen in Alzheimer disease. This revised version was published online in July 2006 with corrections to the Cover Date.