共查询到20条相似文献，搜索用时 31 毫秒
1.
Qi L Heredia JE Altarejos JY Screaton R Goebel N Niessen S Macleod IX Liew CW Kulkarni RN Bain J Newgard C Nelson M Evans RM Yates J Montminy M 《Science (New York, N.Y.)》2006,312(5781):1763-1766
During fasting, increased concentrations of circulating catecholamines promote the mobilization of lipid stores from adipose tissue in part by phosphorylating and inactivating acetyl-coenzyme A carboxylase (ACC), the rate-limiting enzyme in fatty acid synthesis. Here, we describe a parallel pathway, in which the pseudokinase Tribbles 3 (TRB3), whose abundance is increased during fasting, stimulates lipolysis by triggering the degradation of ACC in adipose tissue. TRB3 promoted ACC ubiquitination through an association with the E3 ubiquitin ligase constitutive photomorphogenic protein 1 (COP1). Indeed, adipocytes deficient in TRB3 accumulated larger amounts of ACC protein than did wild-type cells. Because transgenic mice expressing TRB3 in adipose tissue are protected from diet-induced obesity due to enhanced fatty acid oxidation, these results demonstrate how phosphorylation and ubiquitination pathways converge on a key regulator of lipid metabolism to maintain energy homeostasis. 相似文献
2.
LI Xiang ZHOU Qi HE Rui-guo WANG Yu-lian SUN Yun-zi ZHOU Ying YANG Zheng-mei ZHANG Wei 《中国农业科学(英文版)》2005,4(2)
The effect of brown rice and corn-based diets on fatty liver weight, carcass traits, lipids accumulation and liver composition of Landes geese (Anser anser) after feeding the same amount of each diet was investigated. After 2 weeks overfeeding,besides body weight and body weight gain increased significantly, the fatty liver weights were increased dramatically from 94.67 to 554.67 and 754.00 g in corn treatment and rice treatment, respectively, and the accumulation lipids in adipose tissues reached up to or close to 2 folds of initial weight in both treatments. Liver weight was greater in brown rice group than in corn group(P＜0.05). Compared to before overfeeding, triacylglycerols (TG) in geese fatty liver increased dramatically and predominated (from 9.08% to close to or more than 90% of hepatic lipids), whereas phospholipids (PL) and cholesteryl esters (CE) decreased sharply in both treatments (P＜0.05). However, the percentages of lipids, TG and PL in fatty liver were higher in brown rice treatment than in corn treatment, and that of CE was lower (P＜0.05). It indicates that overfeeding chiefly results in lipids accumulation in goose fatty liver and adipose tiss ues. Brown rice-based diet induces greater fatty liver, and brown rice is one of high quality overfeeding ingredients instead of corn. 相似文献
3.
Mitochondria from brown adipose tissue of cold-acclimated rats (6 degrees C) oxidize alpha-ketoglutarate at a rate twice that of controls (26 degrees C). In both groups, however, the phosphorus: oxygen ratio with alpha-ketoglutarate never exceeded unity, and it is essentially zero with either succinate or alpha-glycerophosphate. Adenosine triphosphatase activity of these mitochondria is very low and it is not stimulated by 2,4-dinitrophenol. In addition, both respiration and phosphorylation are unaffected by adenosine diphosphate, 2,4-dinitrophenol, bovine serum albumin, or glutathione. Endogenous respiration of tissue slices is not stimulated by 2-4-dinitrophenol. It is suggested that brown fat mitochondria are not capable of oxidative phosphorylation, but do phosphorylate at the substrate level. Since these findings provide an unusual example of electron transport by means of an energetically nonconservative pathway, their significance to thermogenesis by brown adipose tissue is particularly emphasized. 相似文献
4.
Zimmermann R Strauss JG Haemmerle G Schoiswohl G Birner-Gruenberger R Riederer M Lass A Neuberger G Eisenhaber F Hermetter A Zechner R 《Science (New York, N.Y.)》2004,306(5700):1383-1386
Mobilization of fatty acids from triglyceride stores in adipose tissue requires lipolytic enzymes. Dysfunctional lipolysis affects energy homeostasis and may contribute to the pathogenesis of obesity and insulin resistance. Until now, hormone-sensitive lipase (HSL) was the only enzyme known to hydrolyze triglycerides in mammalian adipose tissue. Here, we report that a second enzyme, adipose triglyceride lipase (ATGL), catalyzes the initial step in triglyceride hydrolysis. It is interesting that ATGL contains a "patatin domain" common to plant acyl-hydrolases. ATGL is highly expressed in adipose tissue of mice and humans. It exhibits high substrate specificity for triacylglycerol and is associated with lipid droplets. Inhibition of ATGL markedly decreases total adipose acyl-hydrolase activity. Thus, ATGL and HSL coordinately catabolize stored triglycerides in adipose tissue of mammals. 相似文献
5.
Nisoli E Clementi E Paolucci C Cozzi V Tonello C Sciorati C Bracale R Valerio A Francolini M Moncada S Carruba MO 《Science (New York, N.Y.)》2003,299(5608):896-899
Nitric oxide was found to trigger mitochondrial biogenesis in cells as diverse as brown adipocytes and 3T3-L1, U937, and HeLa cells. This effect of nitric oxide was dependent on guanosine 3',5'-monophosphate (cGMP) and was mediated by the induction of peroxisome proliferator-activated receptor gamma coactivator 1alpha, a master regulator of mitochondrial biogenesis. Moreover, the mitochondrial biogenesis induced by exposure to cold was markedly reduced in brown adipose tissue of endothelial nitric oxide synthase null-mutant (eNOS-/-) mice, which had a reduced metabolic rate and accelerated weight gain as compared to wild-type mice. Thus, a nitric oxide-cGMP-dependent pathway controls mitochondrial biogenesis and body energy balance. 相似文献
6.
Adipsin: a circulating serine protease homolog secreted by adipose tissue and sciatic nerve 总被引：8，自引：0，他引：8
K S Cook H Y Min D Johnson R J Chaplinsky J S Flier C R Hunt B M Spiegelman 《Science (New York, N.Y.)》1987,237(4813):402-405
Adipsin is a serine protease homolog whose primary structure was predicted from the nucleotide sequence of a differentiation-dependent adipocyte messenger RNA. Immunoblots probed with antisera to synthetic peptides identify two forms of adipsin that are synthesized and secreted by 3T3 adipocytes. These proteins of 44 and 37 kilodaltons are converted to 25.5 kilodaltons by enzymatic deglycosylation. Although adipsin is principally synthesized in adipose tissue, it is also produced by sciatic nerve and is found in the bloodstream. Because of the apparent restriction of adipsin synthesis to tissues highly active in lipid metabolism, its presence in serum, and its modulation in altered metabolic states, this molecule may play a previously unrecognized role in systemic lipid metabolism or energy balance. 相似文献
7.
Haemmerle G Lass A Zimmermann R Gorkiewicz G Meyer C Rozman J Heldmaier G Maier R Theussl C Eder S Kratky D Wagner EF Klingenspor M Hoefler G Zechner R 《Science (New York, N.Y.)》2006,312(5774):734-737
Fat tissue is the most important energy depot in vertebrates. The release of free fatty acids (FFAs) from stored fat requires the enzymatic activity of lipases. We showed that genetic inactivation of adipose triglyceride lipase (ATGL) in mice increases adipose mass and leads to triacylglycerol deposition in multiple tissues. ATGL-deficient mice accumulated large amounts of lipid in the heart, causing cardiac dysfunction and premature death. Defective cold adaptation indicated that the enzyme provides FFAs to fuel thermogenesis. The reduced availability of ATGL-derived FFAs leads to increased glucose use, increased glucose tolerance, and increased insulin sensitivity. These results indicate that ATGL is rate limiting in the catabolism of cellular fat depots and plays an important role in energy homeostasis. 相似文献
8.
鸭梨黑心病与果表蜡质相关性的扫描电镜分析 总被引：2，自引：0，他引：2
应用扫描电镜对黑心病不同发病阶段的鸭梨果表蜡质变化情况进行了观察分析。结果表明,随着黑心病的发生发展,鸭梨果表蜡质逐渐减少。健康果实表面的皮孔和表皮细胞由丰厚的蜡质遮盖,病果表面蜡质稀少且较薄,表皮裂沟变宽变长,皮孔处则细胞裸露。文章对黑心病与果表蜡质变化的关系进行了讨论。 相似文献
9.
Microsomal particles prepared from isolated rat adipose cells take up D-glucose more rapidly than L-glucose. The rate of D-glucose uptake, but not that of L-glucose, is stimulated by incubation of the intact cells with insulin at concentrations as low as 10 microunits per milliliter before disruption and preparation of the microsomes. 相似文献
10.
11.
Metastatic hibernomas in transgenic mice expressing an alpha-amylase-SV40 T antigen hybrid gene 总被引：5，自引：0，他引：5
N Fox R Crooke L H Hwang U Schibler B B Knowles D Solter 《Science (New York, N.Y.)》1989,244(4903):460-463
Mice transgenic for a hybrid gene containing the liver promoter of the mouse amylase gene (Amy-1a) fused to the SV40 tumor antigen coding region unexpected developed malignant brown adipose tissue tumors (malignant hibernomas). Expression of the alpha-amylase gene had previously been thought to be confined to the liver parotid, and pancreas; however, analysis of white and brown adipose tissue from nontransgenic mice revealed expression of the endogenous Amy-1a gene in these tissues. Gene constructs driven by the Amy-1a liver promoter thus provide a means of targeting gene expression to the adipocyte cell lineage in transgenic mice. Moreover the high frequency of metastases in the liver, lungs, spleen, heart, and adrenals of these mice provides an experimental system in which to study the development of disseminated malignancy. 相似文献
12.
G F Schreiner W Flye E Brunt K Korber J B Lefkowith 《Science (New York, N.Y.)》1988,240(4855):1032-1033
A central hypothesis in transplantation biology is that resident leukocytes expressing class II histocompatibility antigens may determine the immunogenicity of an organ. By means of a novel method to deplete the kidney of resident leukocytes, essential fatty acid deficiency (EFAD), this hypothesis was tested in an intact, vascular organ. Kidneys subjected to EFAD and thus depleted of resident Ia-positive macrophages survived and functioned when transplanted across a major histocompatibility antigen barrier in the absence of immunosuppression of the recipient. Control allografts were rejected promptly. Allografts from donors subjected to EFAD normalized their lipid composition and were repopulated with host macrophages by 5 days. Administration of Ia-positive cells at the time of transplantation established that the resident leukocyte depletion induced by EFAD was responsible for the protective effect. These observations may provide insights into the mechanisms underlying tissue immunogenicity and the population of normal tissues with resident leukocytes. 相似文献
13.
The stable carbon isotope (delta13C) compositions of individual fatty acid components of remnant fats preserved in archaeological pottery vessels show that dairying was a component of archaeological economies. Characteristic delta13C values arise from biases in the biosynthetic origins of the C18:0 fatty acids in milk and adipose fat. Milk and adipose fat from animals raised on similar pastures and fodders have distinct isotopic signatures. 相似文献
14.
【目的】旨在阐明患脂肪肝奶牛体内代谢、内分泌以及肝和脂肪中3个基因表达的变化。【方法】分别对10头患脂肪肝奶牛和10头健康奶牛进行血液指标和肝脂含量的检测,利用半定量RT-PCR检测奶牛肝PEPCK-C mRNA的丰度,应用实时荧光定量PCR检测脂肪Lp mRNA和HSL mRNA的丰度。【结果】①脂肪肝奶牛血糖浓度显著降低（P＜0.01）,血浆NEFA和BHBA的浓度显著升高（P＜0.01）,肝脂（约41.98%左右）和血清AST活性显著增加（P＜0.01）,血清γ-GT、TBI、CHE显著升高（P＜0.05）;②脂肪肝奶牛Ins浓度、Ins/Gn明显升高（P＜0.05）,肝PEPCK-C和脂肪HSL mRNA表达水平显著降低（P＜0.05）;③脂肪Lp mRNA表达水平和血浆Lp、NPY浓度显著下降（P＜0.05）。【结论】患脂肪肝奶牛存在严重的能量代谢障碍和明显的肝功障碍,体内Ins与Gn、Lp与NPY之间失调,肝PEPCK-C和脂肪HSL、Lp的基因表达减弱,是病牛能量代谢障碍发生的重要机制。 相似文献
15.
【背景】目前已有相关动物实验证实荞麦对于高脂膳食引起的肥胖和脂代谢紊乱具有良好的干预作用。同时研究表明,棕色脂肪适应性产热可以有效改善人体能量新陈代谢。因此,增加棕色脂肪活性、促进白色脂肪棕色化可作为一种预防肥胖和改善能量代谢疾病的有效途径。【目的】采用原粮及从荞麦中鉴定出的4种主要酚类物质按在原粮中的含量比例配制成多酚干预物进行干预,研究荞麦多酚通过调节白色脂肪棕色化对高脂膳食小鼠的干预及改善作用,系统研究荞麦中发挥降脂功能的主要酚类物质及其对脂代谢的调控机制。【方法】通过UHPLC-Q-Orbitrap质谱结合数据库对荞麦多酚提取物中的酚类物质进行鉴定,并通过相对定量将其中含量最多的主要多酚按其在荞麦原粮中的含量比例配制成多酚复合物。通过添加荞麦饲料以及荞麦多酚复合物干预C57BL/6J小鼠饮食,研究荞麦酚类物质改善脂质代谢的作用。以10%、20%、40%比例的荞麦替换基础饲料和2.5 mg·mL-1荞麦多酚复配物对小鼠进行饮食干预,探究荞麦对小鼠体重、脏器指数和血脂水平的调节作用。并通过Western-blot和q-PCR探究荞麦饲料及多酚干预对小鼠皮下脂肪... 相似文献
16.
17.
从绵羊脂肪组织提取总RNA方法的改进及应用 总被引：4，自引：2，他引：2
以绵羊脂肪组织为材料,对脂肪组织总RNA提取方法进行了改进,并分析了脂肪酸合成酶基因(fattyacid synthase,FAS)在绵羊腹部皮下脂肪组织、肠系膜脂肪组织和尾部脂肪组织中表达的差异性.结果表明:利用改进后的方法从绵羊脂肪组织中提取出的RNA无DNA污染、均一、完整、质量可靠.绵羊腹部皮下脂肪中FASmRNA的表达量极显著高于尾部脂肪组织和肠系膜脂肪组织(P<0.01),且尾部脂肪组织和肠系膜脂肪组织中FAS mRNA的表达量差异不显著(P>0.05). 相似文献
18.
为了对小鼠胚胎附植前后瘦素与脂肪细胞变化的相关性进行研究,本研究采用ELISA方法对小鼠生殖周期不同阶段的血清中的瘦素浓度进行了检测,皮下脂肪组织冰冻切片用苏丹(Ⅲ)染色计量脂肪细胞数量和大小的变化,用免疫组织化学染色法对胃瘦素长型受体进行定位分析。结果显示:妊娠期血清瘦素浓度高于间情期,且瘦素浓度从间情期到妊娠4日龄,呈上升趋势,妊娠5日龄稍下降,然后随妊娠日龄逐渐增加,与单位面积内脂肪细胞数量的变化趋势一致。妊娠7日龄,单位面积内脂肪细胞比间情期少,单个细胞面积大。胃底腺中下部部分胞质和细胞核有棕褐色阳性颗粒且阳性率随妊娠日龄的增加而增加。表明小鼠胚泡附植前后脂肪组织越多血清瘦素水平越高,瘦素及其长型受体可能通过影响胃的消化吸收达到调节机体能量平衡的目的。 相似文献
19.
Brain edema: induction in cortical slices by polyunsaturated fatty acids 总被引：18，自引：0，他引：18
The presence of polyunsaturated and saturated fatty acids in leukocytic membranes prompted study of their possible role in the induction of brain edema. Polyunsaturated fatty acids including sodium arachidonate, sodium linoleate, sodium linolenate, and docasahexaenoic acids induced edma in slices of rat brain cortex. This cellular edema was specific, since neither saturated fatty acids nor a fatty acid containing a single double bond had such effect. 相似文献
20.
钙调素拮抗剂CPZ对苹果果实生理特性的影响 总被引：1，自引：0，他引：1
关军锋 《山东农业大学学报(自然科学版)》1989,20(4):17-22
钙调素拮抗剂CPZ(氯丙嗪)促进苹果果实与果肉切片衰老。CPZ处理降低了果肉超氧化物岐化酶活性,增高了膜脂过氧化产物丙二醛含量,增大了果肉细胞膜透性。CPZ处理导致果实膜系统受损,进而对果实生理特性产生不良影响。 相似文献