瘦素抵抗肥胖大鼠脂肪组织SOCS-3、PPARγ及ACO mRNA水平的探讨

目的观察高脂饮食诱导的肥胖瘦素抵抗大鼠细胞因子信号转导抑制因子-3(SOCS-3)、过氧化物酶体增殖物激活受体γ(PPARγ)及乙酰辅酶A氧化酶(ACO)mRNA表达水平的变化。方法30只Wistar雄性大鼠,6只为对照组喂饲基础饲料,24只为高脂组喂饲高脂饲料,第8周末按体重增量从高脂组中筛选出8只大鼠作为肥胖组,测定对照组和肥胖组大鼠血清瘦素,附睾脂肪组织中SOCS-3,PPARγ以及ACO mRNA表达。结果肥胖组大鼠体重以及血清瘦素水平均显著高于对照组(P<0.05);肥胖组脂肪组织SOCS-3、PPARγ mRNA水平显著高于对照组(P<0.05),而ACO mRNA则显著低于对照组(P<0.05)。结论高脂饮食诱导的肥胖大鼠存在瘦素信号转导通路的抑制,脂肪酸氧化能力降低,脂肪合成能力增强。     

肥胖和肥胖抵抗大鼠脂肪组织PPARγ和aP2基因表达的研究

目的观察高脂饮食诱导的肥胖及肥胖抵抗大鼠脂肪组织中PPARγ和aP2 mRNA表达水平的变化。方法31只健康wistar雄性大鼠,随机选取7只作为对照组喂饲基础饲料,24只作为高脂组喂饲高脂饲料。第8周末按体重增量,从高脂组选出5只大鼠作为肥胖组,5只作为肥胖抵抗组,检测各组大鼠血清甘油三酯和总胆固醇,附睾周围脂肪组织中PPARγ和aP2 mRNA表达。结果肥胖组大鼠血清甘油三酯水平显著高于对照组(P<0.05);总胆固醇水平均显著高于对照组和肥胖抵抗组(P<0.05,P<0.01);肥胖组PPARγ和aP2 mRNA表达量高于对照组和肥胖抵抗组(P<0.05)。结论高脂饮食诱导产生的肥胖及肥胖抵抗大鼠在脂肪组织PPARγ和aP2 mRNA表达上存在差异,肥胖大鼠脂肪合成能力增强。     

共轭亚油酸对肥胖大鼠PPARγ基因表达及血清瘦素水平的影响

目的　研究不同剂量共轭亚油酸 (CLA)对饮食诱导肥胖大鼠PPARγ基因、瘦素、血糖、血脂的影响。方法　选用雄性Wistar大鼠 ,随机分为对照组、高脂组、高脂 +CLA组 (每 10 0g饲料含CLA分别为 0 75g、1 5 0g、3 0 0g) ,于第 12周末处死动物 ,计算脂 体比 ,测定大鼠血糖、血脂及瘦素水平 ,并应用RT PCR的方法检测大鼠白色脂肪组织过氧化物酶体增殖物激活受体γ(PPARγ)的表达水平。结果　CLA可降低肥胖大鼠血糖、甘油三酯 (TG)、总胆固醇 (TC)及瘦素水平 ,增加脂肪组织PPARγmRNA的表达水平。结论　CLA可降低肥胖大鼠血糖、血脂 ,并可通过激活PPARγ下调瘦素水平 ,有改善肥胖大鼠的瘦素抵抗作用。     

粗杂粮对大鼠脂代谢紊乱干预作用的机制探讨

目的观察粗杂粮对大鼠脂代谢紊乱及其脂肪组织过氧化物酶体增殖物激活受体γ (PPARγ) mRNA表达水平的影响,探讨粗杂粮改善脂代谢紊乱的作用机制。方法44只SPF级大鼠随机分为阴性对照组(饲常规饲料)和3个实验组(饲高脂饲料6周),造模成功后分别给予高脂粗杂粮、高脂米面和高脂模型饲料共15周。结果粗杂粮高脂组的血清总胆固醇(TC)、总甘油三酯(TG)、白细胞介素-6(IL-6)和C反应蛋白(CRP)显著低于高脂模型组(P<0.05),血清高密度脂蛋白胆固醇(HDL-C)水平显著高于高脂模型和米面高脂组(P<0.05),脂蛋白酯酶(LPL)和肝酯酶(HL)活性及肿瘤坏死因子-α(TNF-α)最接近阴性对照组水平;粗杂粮高脂组白色脂肪组织PPARγ mRNA的表达水平明显高于高脂模型组和米面高脂组(P<0.05)。结论复配式粗杂粮可以激活PPARγ,促进脂肪细胞LPL和HL活性逐步恢复,使血脂水平下降;同时抑制和减少IL-6、TNF-α及CRP的产生,炎症反应减轻,脂代谢紊乱得到改善。     

共轭亚油酸对胰岛素抵抗大鼠ap2基因表达的影响

目的通过研究共轭亚油酸(CLA)对饮食诱导胰岛素抵抗大鼠脂肪酸连接蛋白(ap2)基因表达的影响,探讨CLA抗糖尿病作用的机制。方法选用雄性Wistar大鼠,随机分为对照组、高脂组、高脂+CLA组(每100g饲料含CLA分别为0·75g、1·50g、3·00g),每组动物10只,观察CLA对胰岛素抵抗大鼠胰岛素、血糖水平的影响,并应用RT-PCR的方法检测ap2、过氧化物酶体增殖物活性受体γ(PPARγ)的表达水平。结果高脂组大鼠血清游离脂肪酸(FFA)、胰岛素和糖血水平显著高于基础组,CLA可降低胰岛素抵抗大鼠血清FFA、血糖、胰岛素水平,并可增加其脂肪组织ap2、PPARγmRNA的表达水平。结论CLA可通过激活PPARγ上调脂肪酸连接蛋白基因的表达,改善肥胖大鼠的胰岛素抵抗。     

不同脂肪酸对脂肪细胞脂联素及PPARγ基因表达影响

目的用不同种类、不同浓度的脂肪酸处理体外培养的3T3-L1成熟脂肪细胞,观察处理前后脂联素(ad-iponectin)及过氧化物酶体增殖物激活受体γ(PPARγ)基因mRNA的表达水平,及两者之间是否存在相互关系。方法运用实时荧光定量PCR方法检测体外培养并诱导分化成熟的3T3-L1脂肪细胞经一定浓度脂肪酸处理后,脂联素及PPARγ基因mRNA的表达水平。结果棕榈酸(PA)在低浓度(25μmol/L)时能明显上调脂联素及PPARγmRNA的表达,比对照组增加53%(P<0.05),其余浓度均呈表达下降;油酸(OA)和亚油酸(LA)则在浓度为25、50、100μmol/L时上调脂联素及PPARγmRNA的表达,在50μmol/L时上调作用最为明显,随着浓度的继续增加脂联素表达下降,呈剂量依赖关系,浓度越高,表达越低。结论油酸和亚油酸在一定浓度范围内上调3T3-L1脂肪细胞脂联素基因表达,棕榈酸则主要表现为抑制作用,但在很低浓度(25μmol/L)时也上调脂联素表达;脂联素基因表达与PPARγ基因表达相关。     

二十二碳六烯酸对3T3-L1脂肪细胞脂联素mRNA的影响及其机制

目的探讨二十二碳六烯酸(docosahexaenoic acid,DHA)对3T3-L1脂肪细胞脂联素表达的影响及其机制。方法不同浓度DHA处理体外培养成熟的3T3-L1脂肪细胞,并选取一定浓度DHA加与不加过氧化物酶体增殖物激活受体γ(PPARγ)拮抗剂GW-9662处理脂肪细胞,实时荧光定量PCR分析处理前后脂联素基因和PPARγmRNA表达水平的差异。结果与对照组相比,当DHA浓度为50、100 mol/L时,脂联素表达水平分别增加71.89%、106.23%(P<0.05),随着浓度的增加脂联素表达降低,当DHA浓度达到400 mol/L时,脂联素表达水平最低(P<0.05)。当DHA浓度为100 mol/L时,脂肪细胞PPARγmRNA表达增加70.24%(P<0.05)。与对照组相比,DHA中加GW-9662处理组脂联素和PPARγmRNA表达水平分别降低97.32%、90.90%(P<0.05)。结论在一定浓度范围内,DHA对脂联素表达的影响呈剂量依赖关系,推测DHA可能是通过PPARγ途径调控脂肪细胞的脂联素表达。     

共轭亚油酸对饮食诱导肥胖大鼠脂代谢及相关基因表达的影响

目的:通过研究共轭亚油酸(CLA)对饮食诱导肥胖大鼠脂肪酸转移蛋白、酰基CoA合成酶基因表达的影响,探讨CLA抗糖尿病机制。方法:选雄性Wistar大鼠,随机分为对照组、高脂组、高脂+CLA组(每100g饲料含CLA分别为0.75、1.50、3.00g),每组动物10只,观察CLA对肥胖大鼠血清游离脂肪酸(FFA)、胰岛素、血糖水平的影响,并应用RT-PCR法检测脂肪酸转移蛋白(FATP)、酰基CoA合成酶(ACS)、过氧化物酶体增殖物活性受体γ(PPARγ)mRNA的表达水平。结果:高脂组大鼠血清FFA、胰岛素和血糖水平显著高于对照组,CLA可降低肥胖大鼠血清FFA、胰岛素、血糖水平,并且可增加肥胖大鼠脂肪组织FATP、ACS、PPARγmRNA的表达水平。结论:CLA可通过激活PPARγ上调FATP、ACS基因的表达,改善肥胖大鼠的胰岛素抵抗。     

全氟辛酸对大鼠肝脏氧化应激与PPARα及其所调控的CYP4A1基因表达的影响

目的研究全氟辛酸(perfluorooctanoic acid,PFOA)致大鼠肝脏氧化应激以及对过氧化物酶体增殖剂激活受体(PPAR)α、细胞色素P450(CYP)4A1基因以及PPARα蛋白表达的影响。方法将28只雄性SD大鼠随机分为4组,每组7只,分别为对照组(双蒸水)、低剂量组[PFOA 1 mg/(kg·d)]、中剂量组[PFOA 5 mg/(kg·d)]和高剂量组[PFOA 25 mg/(kg·d)],连续14 d经口灌胃后处死,称重肝脏并计算肝脏系数。用生化检测试剂盒测定大鼠肝脏组织总超氧化物歧化酶(T-SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性以及丙二醛(MDA)含量;荧光定量PCR检测PPARα及CYP4A1基因的mRNA转录水平;Western blot检测PPARα蛋白表达水平。结果从灌胃第5天开始,高剂量组体重与对照组差异有统计学意义(P<0.05)。中、高剂量组肝脏重量和肝脏系数与对照组相比,均显著升高(P<0.05)。低剂量组大鼠肝脏SOD和GSH-Px活性与对照组相比显著升高(P<0.05);中、高剂量组大鼠肝脏MDA含量是对照组2.5倍和3.5倍(P<0.05)。低、中、高剂量组PPARα及其所调控的CYP4A1基因mRNA表达水平均被显著诱导升高。低、中、高剂量组PPARα蛋白表达均上调(P<0.05)。结论 PFOA暴露可导致大鼠肝脏氧化应激,从而引起SOD和GSH-Px以及MDA的变化。同时,PFOA暴露可诱导大鼠肝脏的PPARα、CYP4A1基因表达上调,可增强脂肪酸β氧化,从而导致脂质过氧化产生,对大鼠肝脏有明显的毒性作用。     

过氧化物酶体增殖物激活受体基因甲基化与子痫前期的相关性分析

目的探讨过氧化物酶体增殖物激活受体(PPARα)基因启动子的甲基化水平及基因表达情况与子痫前期之间的相关性。方法选取2016年11月-2017年8月在甘肃省妇幼保健院产科分娩的67例子痫前期患者为观察组,56例正常分娩产妇为对照组。应用甲基化特异度聚合酶链反应(MSP)法和RT-PCR技术分析PPARα基因启动子区Cp G位点的甲基化水平及其mRNA表达情况。结果观察组患者外周血和胎盘组织PPARα基因63位点的甲基化程度明显低于对照组,差异均有统计学意义(均P0. 05)。观察组患者胎盘的PPARα基因mRNA表达量明显高于对照组,其外周血中蛋白浓度也显著高于对照组,差异均有统计学意义(均P0. 05)。胎盘组织和外周血的甲基化率呈显著正相关关系(r=0. 84,P0. 01)。结论 PPARα基因启动子区域Cp G位点低甲基化变化与子痫前期具有相关性。子痫前期发病可能与母体自身密切相关。     

Conjugated linoleic acid differentially modifies fatty acid composition in subcellular fractions of muscle and adipose tissue but not adiposity of postweaning pigs

This study examined the interaction between conjugated linoleic acid (CLA) and dietary fat type on the enrichment of subcellular fractions, the Delta(9) desaturase index and adiposity in pigs. Early weaned piglets (n = 6/group) were fed for 35 d diets supplemented with 15 g/100 g diet beef tallow or corn oil, or 12 g/100 g tallow or corn oil plus 3 g CLA. There were no effects of dietary fat or CLA on the mass of dissected skin, bone, muscle or adipose tissue of the 7th to 9th thoracic rib sections. Medial subcutaneous adipose tissue of pigs fed tallow had smaller adipocytes than that of pigs fed corn oil. The lateral subcutaneous site was unaffected by dietary fat type. Microsomes accumulated <50% the concentration of trans-10,cis-12, cis-11,trans-13, and cis-9,trans-11 CLA as membrane and nonmembrane fractions of adipose tissue and longissimus muscle. There was no evidence of preferential incorporation of any CLA isomer into any of the subcellular fractions. Addition of CLA to the diets reduced adipose tissue nonmembrane monounsaturated fatty acids (MUFA; g/100 g total fatty acids) by 15% in corn oil-fed pigs and by 19% in tallow-fed pigs. Total saturated fatty acids (SFA) were increased by CLA commensurately in this lipid fraction. This resulted in a reduced Delta(9) desaturase index [MUFA/(SFA + MUFA)] in the nonmembrane lipid fraction of pigs fed either the corn oil or tallow diets. Thus, in spite of marked effects on fatty acid composition and the Delta(9) desaturase index, CLA had no effect on adiposity in early weaned piglets fed high fat diets.     

Digestion rate of dietary starch affects the systemic circulation of lipid profiles and lipid metabolism-related gene expression in weaned pigs

The present study was conducted to investigate the effect of digestion rate of dietary starch on postprandial systemic circulating glucose, insulin and lipid profiles, and the activity and gene expression of lipid metabolism-related enzymes in weaned pigs. A total of twenty-four weaned pigs, surgically fitted with a catheter in the jugular vein, were randomly assigned to three dietary treatment groups, representing the high digestion rate starch (HDRS) group, the moderate-digestion rate starch (MDRS) group and the low-digestion rate starch (LDRS) group. The amylopectin:amylose ratios in the diets of each group were 27·6:1, 27·6:8·5 and 1:27·6, respectively. The serum concentrations of glucose, TAG, total cholesterol, LDL-cholesterol and HDL-cholesterol in the HDRS group were increased to the peak point at postprandial 1·5, 2·5, 2·5, 1·5 and 1·5?h, those in the MDRS group were at postprandial 2·5, 3·5, 3·5, 3·5 and 3·5?h and those in the LDRS group were at postprandial 2·5, 3·5, 3·5, 1·5 and 3·5?h, respectively. The serum concentration of insulin in the HDRS group was higher (P?相似文献   

普洱茶提取物对饮食诱导肥胖大鼠脂质合成相关基因表达的影响

目的观察普洱茶提取物(PTE)对饮食诱导性肥胖大鼠脂质合成相关基因的影响,探讨普洱茶抗肥胖的作用机制。方法30只雄性Sprague-Dawley大鼠随机分为3组(n=10):正常对照组,普通饲料;高脂组,高脂饲料;高脂+PTE组,高脂饲料+PTE。采用高脂饲料建立肥胖大鼠模型,测定大鼠体重和脂肪组织重量,判定减肥效果;采用real-timePCR检测PTE对脂质合成相关基因的表达影响。结果PTE能有效减轻动物体重和脂肪组织重量,显著下调二酰基甘油酰转移酶-1(DGAT1)、固醇辅酶A去饱和酶1(SCD1)和固醇调节元件结合蛋白(SREBP)-1cmRNA的表达。结论PTE可通过调节脂质合成相关基因,减少脂肪的合成,达到预防肥胖的作用。     

The function of the nuclear receptor peroxisome proliferator-activated receptor delta in energy homeostasis

The metabolic function of the nuclear receptor peroxisome proliferator-activated receptor delta (PPAR(delta)) has been established by transfer of the PPAR(delta) gene into adipose tissue of mice in vivo and into adipocytes in culture. Investigators found that PPAR(delta) activation by such transfer leads to up-regulation of energy expenditure by fatty acid oxidation. PPAR(delta) activation also results in lowered serum triglyceride and free fatty acid levels and decreased lipid accumulation. In vivo activation of PPAR(delta) in adipose tissue protects against obesity and fatty liver in mice fed a high-calorie diet. PPAR(delta) also activates the heat-producing uncoupling enzymes in brown adipose tissue (UCP1 and 3) and muscle (UCP2).     

中链甘油三酯饮食增加过氧化物酶增殖体激活受体γ和脂联素的表达

目的探讨含中链甘油三酯(medium chain triglycerides,MCT)的高脂饮食对血清和脂肪组织中脂联素、过氧化物酶增殖体激活受体γ(PPARγ)水平的影响。方法雄性Wistar大鼠,分别饲喂含MCT和长链甘油三酯(LCT)的高脂饲料,8w后病理检测右侧肾周脂肪细胞的大小。ELISA法检测血清中脂联素、TNF-α、胰岛素的水平。逆转录PCR测定脂肪组织中脂联素、PPARγ mRNA表达水平。结果MCT组大鼠体脂(BFA)、外周脂肪组织的细胞直径小于LCT组。MCT组的血清脂联素含量高于LCT组,两组间血清TNF-α无显著差异。MCT组外周脂肪组织中脂联素、PPARγ mRNA表达水平显著高于LCT组。结论MCT饮食可通过促进PPARγ表达,上调脂联素基因的表达,改善大鼠胰岛素抵抗。     

Reduced tissue arachidonic acid concentration with chronic ethanol feeding in miniature pigs.

The effect of ethanol feeding on the essential fatty acid content of tissues has been contradictory. To define the effect, we analyzed fatty acid profiles in various tissues from five miniature pigs fed daily 105 kJ basal diet/kg body wt and 146 kJ ethanol/kg body wt, and also five control pigs pair-fed the same amount of basal diet but with corn starch substituted for ethanol. After 12 mo, biopsy samples were taken, and tissue fatty acid profiles were analyzed. In the phospholipid fraction from the ethanol group there was a uniform decrease in arachidonic acid (AA) and an increase in oleic acid in liver, serum, and muscle. AA was consistently decreased in the triglyceride fractions of liver, serum and subcutaneous adipose of the ethanol group. Possible explanations for this general reduction in tissue AA with ethanol feeding include decreased activities of delta 6 and delta 5 desaturases, and a displacement of AA from lipid fractions by other fatty acids.     

Antiobesity effect of oil extract of ginseng

In a preliminary study we found that incubating raw ginseng in oil facilitated autolysis and extensive metabolism of ginseng, releasing flavor and lipophilic compounds into the oil so that it could be used as an ingredient for high value-added foods, while the residue could be utilized for making ginseng extract. Here, we report the effect of oil (grapeseed oil [GSO]) extract of ginseng (OEG) on body weight gain and lipid metabolism in a mouse model. OEG, but not GSO, inhibited porcine pancreatic lipase. Plasma triglyceride (TG) levels were lower in male ICR mice at 1, 2, 3, and 4 hours after oral administration of the lipid emulsion plus OEG (1?g/kg of body weight) than in the group administered only the lipid emulsion or lipid emulsion plus GSO. Next, male C57BL/6J mice were fed a standard diet, a high fat (HF) diet containing 30% lard, or diets including 30% OEG or GSO based on the standard diet for 14 weeks. Consumption of OEG-containing diet significantly lowered the body weight gain, feed efficiency, visceral fat accumulation, plasma TG, and hepatic and white epididymal adipocyte sizes, as well as expression of peroxisome proliferator-activated receptor γ (PPARγ) in liver and adipose tissue. In conclusion, dietary OEG improved obesity-related parameters in blood, liver, and adipose tissue in a mouse model and suppressed obesity induced by HF diet, possibly by regulating lipid metabolism by modulating PPARγ protein expression.