干扰山羊KLF12促进皮下脂肪细胞分化

[背景]脂肪组织分为皮肤下的皮下脂肪组织(subcutaneous adipose tissue,SAT)和腹部内器官周围的内脏脂肪组织(visceral adipose tissue,VAT),皮下脂肪作为影响肉类美味与否的重要因素,探究皮下脂肪沉积分子调控机制对于育种改良和畜牧业的发展至关重要.Krüppel-li...     

胰岛素、胰高血糖素对体外培养脂肪细胞FAS mRNA表达的影响

为阐明胰岛素、胰高血糖素与脂肪酸合成酶（FAS）的关系,在体外培养良好的脂肪细胞中添加不同浓度的胰岛素（INS）、胰高血糖素（GLU）,每个激素设置6个浓度梯度,培养12h后,通过荧光定量PCR技术,观测胰岛素、胰高血糖素对FAS mRNA丰度的影响。结果显示,胰岛素促进了FAS mRNA的表达,而胰高血糖素抑制了FAS mRNA的表达。结果表明,胰岛素和胰高血糖素能直接调控肝细胞中FAS mRNA的表达。     

Differences in adipose tissue inflammation and oxidative status in C57BL/6 and ApoE−/− mice fed high fat diet

Apolipoprotein E deficient (Apo E?/?) mice are more resistant to the development of obesity compared to C57BL/6 wild type mice. They also hold a high basal oxidative status due to the loss of antioxidant action of apolipoprotein E. Since obesity is also an inducer of inflammation, we studied the effect of high‐fat diet on obesity and oxidative stress in C57BL/6 and Apo E?/? mice for 9 weeks. The results confirmed that Apo E?/? mice fed high‐fat diet are more resistant to the increase of both body weight and adiposity compared to C57BL/6 mice. Despite this, Apo E?/? mice presented a higher basal oxidative stress that was enhanced by high‐fat diet. Macrophage infiltration, macrophage forming crown‐like structures and proinflammatory adipokines (interleukin 6 and tumor necrosis factor alpha) were all higher in adipose tissue from Apo E?/? compared to C57BL/6 mice, regardless of diet type. In conclusion, although Apo E?/? mice are more resistant to becoming obese, they develop more severe adipose tissue inflammation companied by its consequences.     

成熟脂肪细胞中脂联素基因表达的脂肪酸应答调控

用不同种类、不同浓度游离脂肪酸(FFA)处理体外培养的成熟3T3-L1脂肪细胞,实时荧光定量PCR和Western-blotting分析FFA处理前后脂联素基因mRNA和蛋白质水平的表达差异.结果表明:各类脂肪酸埘脂联素mRNA的表达均具有下调作用.且抑制效应呈时间、剂量依赖性;并且各种脂肪酸显著地影响脂联素蛋白的分泌作用.     

调控牛CEBPA基因表达的miRNA筛选及对肌内前体脂肪细胞增殖和分化的影响

旨在筛选并验证调控牛增强子结合蛋白A(CCAAT/enhancer binding protein alpha,CEBPA)表达的miRNA及其对肌内前体脂肪细胞增殖和分化的影响.本研究综合运用多个在线软件筛选与CEBPA基因具有潜在调控关系的miRNA,运用qRT-PCR技术检测CEBPA基因在关岭牛各类组织中的表达...     

Effect of dietary ascorbate fortification on lipolysis activity of juvenile black sea bream Acanthopagrus schlegeli

ABSTRACT:   Hatchery-reared black sea bream Acanthopagrus schlegeli juveniles averaging 0.05 g in body weight were fed either a control diet (commercial diet) or an experimental diet in which the commercial diet was fortified with 50 mg l -ascorbyl 2-monophosphate Mg (APM)/100 g diet for 50 days. Calcium ascorbate supplemented as a vitamin mixture in the control diet was completely destroyed during storage. Fortification with APM significantly increased the ascorbic acid levels in the muscle, liver, brain and eye. Although APM fortification did not influence growth, survival or fish body composition, adipocyte diameter in the intraperitoneal fat body (IPF) was significantly reduced. After the feeding experiment, the fish were kept for 39 days without feeding. Fortification with APM resulted in high survival, high muscle protein retention and low body weight loss. The results suggested the necessity of fortification with an adequate amount of ascorbate in the diet. While fatty acid compositions of the IPF, muscle and liver were not significantly influenced by APM fortification, characteristic changes in the fatty acid profile were found after starvation. Vitamin C and highly unsaturated fatty acids seemed crossly interactive in relation to lipolysis activity in black sea bream juveniles.     

TIMP2 promotes intramuscular fat deposition by regulating the extracellular matrix in chicken

The interaction between myocytes and intramuscular adipocytes is a hot scientific topic.  Using a co-culture system, this study aims to investigate the regulation of intramuscular fat deposition in chicken muscle tissue through the interaction between myocyte and adipocyte and identify important intermediary regulatory factors.  Our proteomics data showed that the protein expression of tissue inhibitor of metalloproteinases 2 (TIMP2) increased significantly in the culture medium of the co-culture system, and the content of lipid droplets was more in the co-culture intramuscular adipocytes.  In addition, TIMP2 was significantly upregulated (P<0.01) in muscle tissue of individuals with high intramuscular fat content.  Weighted gene co-expression network analysis revealed that TIMP2 was mainly involved in the extracellular matrix receptor interaction signaling pathway and its expression was significantly correlated with triglyceride, intramuscular fat, C14:0, C14:1, C16:0, C16:1, and C18:1n9C levels.  Additionally, TIMP2 was co-expressed with various representative genes related to lipid metabolism (such as ADIPOQ, SCD, ELOVL5, ELOVL7, and LPL), as well as certain genes involved in extracellular matrix receptor interaction (such as COL1A2, COL4A2, COL5A1, COL6A1, and COL6A3), which are also significantly upregulated (P<0.05 or P<0.01) in muscle tissue of individuals with high intramuscular fat content.  Our findings reveal that TIMP2 promotes intramuscular fat deposition in muscle tissue through the extracellular matrix receptor interaction signaling pathway.     

槲皮素对肉鸡脂肪细胞环腺苷酸信号通路的作用

【目的】研究槲皮素对肉鸡脂肪细胞甘油三酯沉积过程中环腺苷酸（cyclic adenosine monophosphate,cAMP）信号通路的作用。【方法】将脂肪细胞随机分5组,每组6个重复;空白对照组为基础培养液,溶剂对照组为含2‰二甲基亚砜（DMSO）的培养液,试验组为含10、20和40 mg•L-1槲皮素的培养液,分别于24、48和72 h收集细胞及培养液;ELISA法测定乙酰CoA羧化酶（acetyl CoA carboxylase,ACC）、脂肪酸合成酶（fatty acid synthase,FAS）、脂蛋白脂酶（lipoprotein lipase,LPL）、cAMP、腺苷酸环化酶（adenylate cyclase,AC）、磷酸二脂酶（phosphodiesterase,PDE）、蛋白激酶（protein kinase A,PKA）含量;紫外分光光度计测定甘油三酯（triacylglycerides,TG）含量。【结果】与空白对照组相比,①溶剂对照组各指标均无显著差异（P＞0.05）;②20和40 mg•L-1槲皮素组ACC、FAS、LPL、TG和PDE含量显著降低（P＜0.05）,cAMP和PKA含量显著增加（P＜0.05）;③3个槲皮素组AC含量均无显著差异（P＞0.05）。【结论】一定剂量槲皮素可通过调控cAMP信号通路抑制脂肪合成,并减少脂肪沉积。