不同生物素水平对3T3-L1脂肪细胞脂肪分解及相关基因表达的影响

为研究不同生物素水平对3T3-L1脂肪细胞脂肪分解及相关基因表达的影响,本试验利用三联诱导法将3T3-L1细胞经诱导分化为3T3-L1脂肪细胞。当3T3-L1脂肪细胞密集后分别采用0(对照组)、0.2、0.5、1.0μmol/L生物素处理,分别在12、24与48h时检测细胞上清液中甘油释放量、脂肪甘油三酯水解酶(ATGL)、激素敏感性脂肪酶(HSL)、脂滴包被蛋白A(perilipin A)及脂肪分化相关蛋白(ADRP)相对表达量。结果显示,在12h时,1.0μmol/L组甘油释放量、ATGL基因mRNA相对表达量均极显著低于对照组(P0.01),0.5、1.0μmol/L组HSL基因mRNA相对表达量显著低于对照组(P0.05),1.0μmol/L组perilipin A、ADRP基因mRNA相对表达量均极显著高于对照组与0.2μmol/L组(P0.01);在24h时,各试验组甘油释放量、1.0μmol/L组ATGL基因mRNA相对表达量均极显著低于对照组(P0.01),0.5、1.0μmol/L组perilipin A基因mRNA相对表达量极显著高于对照组与0.2μmol/L组(P0.01);1.0μmol/L组ADRP基因mRNA相对表达量极显著高于其他组(P0.01);在48h时,1.0μmol/L组甘油释放量、ATGL基因mRNA相对表达量均极显著或显著低于对照组(P0.01;P0.05),1.0μmol/L组perilipin A基因mRNA相对表达量显著高于对照组与0.2μmol/L组(P0.05),0.5、1.0μmol/L组ADRP基因mRNA相对表达量极显著高于对照组(P0.01)。综上所述,生物素可通过促进perilipin A与ADRP表达,同时抑制ATGL与HSL表达,达到抑制脂肪分解的效果,且浓度为1.0μmol/L时效果最佳。     

不同生物素水平对3T3-L1脂肪细胞脂肪分解及相关基因表达的影响

为研究不同生物素水平对3T3-L1脂肪细胞脂肪分解及相关基因表达的影响，本试验利用三联诱导法将3T3-L1细胞经诱导分化为3T3-L1脂肪细胞。当3T3-L1脂肪细胞密集后分别采用0（对照组）、0.2、0.5、1.0 μmol/L生物素处理，分别在12、24与48 h时检测细胞上清液中甘油释放量、脂肪甘油三酯水解酶（ATGL）、激素敏感性脂肪酶（HSL）、脂滴包被蛋白A （perilipin A）及脂肪分化相关蛋白（ADRP）相对表达量。结果显示，在12 h时，1.0 μmol/L组甘油释放量、ATGL基因mRNA相对表达量均极显著低于对照组（P<0.01），0.5、1.0 μmol/L组HSL基因mRNA相对表达量显著低于对照组（P<0.05），1.0 μmol/L组perilipin A、ADRP基因mRNA相对表达量均极显著高于对照组与0.2 μmol/L组（P<0.01）；在24 h时，各试验组甘油释放量、1.0 μmol/L组ATGL基因mRNA相对表达量均极显著低于对照组（P<0.01），0.5、1.0 μmol/L组perilipin A基因mRNA相对表达量极显著高于对照组与0.2 μmol/L组（P<0.01）；1.0 μmol/L组ADRP基因mRNA相对表达量极显著高于其他组（P<0.01）；在48 h时，1.0 μmol/L组甘油释放量、ATGL基因mRNA相对表达量均极显著或显著低于对照组（P<0.01；P<0.05），1.0 μmol/L组perilipin A基因mRNA相对表达量显著高于对照组与0.2 μmol/L组（P<0.05），0.5、1.0 μmol/L组ADRP基因mRNA相对表达量极显著高于对照组（P<0.01）。综上所述，生物素可通过促进perilipin A与ADRP表达，同时抑制ATGL与HSL表达，达到抑制脂肪分解的效果，且浓度为1.0 μmol/L时效果最佳。     

油酸和亚油酸对山羊乳腺细胞甘油三酯含量及乳脂合成相关基因表达的影响

为探讨外源添加油酸和亚油酸对体外培养的奶山羊乳腺上皮细胞甘油三酯(TG)含量和乳脂肪合成相关基因表达的影响,试验以奶山羊乳腺上皮细胞为研究对象,分别用0、50、100、200μmol/L油酸和0、20、40、80μmol/L的亚油酸处理细胞24h,检测细胞内TG的含量;采用实时荧光定量PCR法检测细胞内乳脂合成相关基因mRNA水平的变化。结果显示,100、200μmol/L的油酸和40、80μmol/L亚油酸均显著促进细胞内TG的合成(P<0.05)。实时荧光定量PCR结果表明,添加100、200μmol/L油酸可显著上调二酰甘油酰基转移酶2(DGAT2)、乙酰辅酶A羧化酶(ACC)及脂肪酸合成酶(FASN)基因的表达(P<0.05),显著抑制硬脂酰辅酶A去饱和酶1(SCD1)基因的表达(P<0.05),而对过氧化物酶体增殖物激活受体γ(PPARγ)基因的表达无显著影响(P>0.05)。添加20μmol/L亚油酸可显著抑制ACC和FASN基因的表达(P<0.05);亚油酸浓度为40和80μmol/L时可显著上调DGAT2基因的表达(P<0.05),抑制SCD1和SREBP1基因的表达(P<0.05),对ACC、FASN和PPARγ基因表达均无显著影响(P>0.05)。综上所述,100～200μmol/L油酸和40～80μmol/L亚油酸对奶山羊乳腺上皮细胞乳脂肪合成具有较好的促进效果。     

油酸和亚油酸对山羊乳腺细胞甘油三酯含量及乳脂合成相关基因表达的影响

为探讨外源添加油酸和亚油酸对体外培养的奶山羊乳腺上皮细胞甘油三酯(TG)含量和乳脂肪合成相关基因表达的影响,试验以奶山羊乳腺上皮细胞为研究对象,分别用0、50、100、200μmol/L油酸和0、20、40、80μmol/L的亚油酸处理细胞24h,检测细胞内TG的含量;采用实时荧光定量PCR法检测细胞内乳脂合成相关基因mRNA水平的变化。结果显示,100、200μmol/L的油酸和40、80μmol/L亚油酸均显著促进细胞内TG的合成(P0.05)。实时荧光定量PCR结果表明,添加100、200μmol/L油酸可显著上调二酰甘油酰基转移酶2(DGAT2)、乙酰辅酶A羧化酶(ACC)及脂肪酸合成酶(FASN)基因的表达(P0.05),显著抑制硬脂酰辅酶A去饱和酶1(SCD1)基因的表达(P0.05),而对过氧化物酶体增殖物激活受体γ(PPARγ)基因的表达无显著影响(P0.05)。添加20μmol/L亚油酸可显著抑制ACC和FASN基因的表达(P0.05);亚油酸浓度为40和80μmol/L时可显著上调DGAT2基因的表达(P0.05),抑制SCD1和SREBP1基因的表达(P0.05),对ACC、FASN和PPARγ基因表达均无显著影响(P0.05)。综上所述,100～200μmol/L油酸和40～80μmol/L亚油酸对奶山羊乳腺上皮细胞乳脂肪合成具有较好的促进效果。     

全反式视黄酸对3T3-L1前脂肪细胞分化及PPARγ和C/EBPα mRNA表达的影响

本研究旨在探讨全反式视黄酸(all trans retinoic acid,ATRA)对3T3-L1前脂肪细胞分化的影响及其机制。培养3T3-L1前脂肪细胞,分别设置对照组以及10-9、10-8、10-7、10-6和10-5 mol/L ATRA的处理组,油红O染色观察3T3-L1前脂肪细胞分化的形态变化;油红O染色提取法分析不同浓度ATRA对3T3-L1前脂肪细胞分化的影响;Real-time PCR技术检测脂肪细胞分化相关基因过氧化物酶体增殖物激活受体γ(peroxisome proliferator activated receptor,PPARγ)、CCAAT/增强子结合蛋白α(CCAAT/enhancer binding proteinα,C/EBPα)mRNA水平的表达。结果表明:10-7、10-6和10-5 mol/L的ATRA抑制3T3-L1前体脂肪细胞的分化(P0.01),而10-9和10-8 mol/L的ATRA对3T3-L1前体脂肪细胞分化没有显著影响(P0.05)。10-5 mol/L的ATRA处理的前脂肪细胞,分化相关基因PPARγ和C/EBPαmRNA的表达减少,与空白对照组比较差异有统计学意义(P0.01)。结果显示,高浓度的ATRA可以抑制3T3-L1前脂肪细胞分化,减少脂肪细胞分化过程中脂质的堆积,机制可能与其抑制脂肪细胞分化相关基因PPARγ和C/EBPαmRNA表达有关。     

驴内脏组织中脂肪沉积相关基因的差异表达

脂肪沉积相关基因在动物内脏中的异常表达与某些疾病相关。应用RT-qPCR技术分别检测2岁~3岁健康公、母新疆驴内脏器官心、脾、肾、肝、小肠、大肠和肺中脂肪沉积相关基因H-FABP、PLIN1、LPL、HSL、PPARγ和FASN的表达差异。结果显示,新疆驴内脏器官中脂肪沉积相关基因的表达,性别对基因的差异表达影响较小;在各组织间,H-FABP基因在心脏、PLIN1基因在肝脏组织中的表达都显著的高于其他组织;LPL、HSL基因在心脏、肾脏的表达量较高;PPARγ基因在脾、肺中表达最高,而FASN基因在心、脾中表达最低。研究结果可为新疆驴内脏器官有关疾病的监测与预防提供一定的参考。     

PPARγ对猪血管内皮细胞增殖、迁移及小管形成的影响

试验旨在研究过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorsγ,PPARγ)对猪血管内皮细胞增殖、迁移及小管形成的影响,并探讨PPARγ在猪体外血管生成中的作用。设置PPARγ激动剂组(5、10、15、20μmol/L罗格列酮)、抑制剂组(5、10、15、20μmol/L T0070907)及对照组,通过iCelligence细胞功能分析、划痕试验和Matrigel基质胶三维培养,构建猪体外血管生成的模型,模拟猪体内血管生成的环境,分别对猪血管内皮细胞的增殖、迁移、小管形成能力进行测定,同时根据NCBI已有的相关序列,应用Primer Premier 5.0软件设计PPARγ基因特异性引物,利用SYBR GreenⅠ实时荧光定量PCR检测PPARγ基因mRNA相对表达量,对PPARγ的体外作用效果进行验证。结果显示,5、10μmol/L罗格列酮能促进猪血管内皮细胞增殖、迁移及小管形成,T0070907的抑制效果在试验浓度区间内(5~15μmol/L)随浓度升高而加强,较高浓度(20μmol/L)的两种药物均由于药物毒性的影响对细胞活动产生干扰。此外,5~20μmol/L罗格列酮和5~20μmol/L T0070907能分别提高和降低PPARγ基因mRNA相对表达量,且浓度趋势与增殖、迁移、小管形成的试验结果一致。综上所述,通过激活PPARγ可以对猪血管内皮细胞的增殖、迁移及小管形成产生促进效果,提示其在猪体外血管生成中具有积极作用,可为研究PPARγ对猪胎盘血管发生的影响提供参考依据。     

miR-137-3p靶向MAX基因对前脂肪细胞3T3-L1成脂分化的影响

【目的】研究miR-137-3p在前脂肪细胞(3T3-L1)分化过程中的功能及作用机制。【方法】收集诱导分化第0、2、4、6和8天的3T3-L1细胞,利用实时荧光定量PCR检测miR-137-3p相对表达量;将miR-137-3p的模拟物(mimics)、抑制物(inhibitor)和阴性对照(NC)分别转染3T3-L1细胞并诱导成脂分化,油红O染色观察脂滴形成情况,利用实时荧光定量PCR检测成脂标志基因CAAT增强子结合蛋白α(C/EBPα)、C/EBPβ、过氧化物酶体增殖物激活受体γ(PPARγ)和脂肪酸结合蛋白4(FABP4)相对表达量,用Western blotting检测C/EBPβ、PPARγ和FABP4蛋白表达水平;利用TargetScan在线网站预测miR-137-3p的靶基因,比对候选靶基因3′-UTR区与miR-137-3p结合位点在不同物种间的序列保守性。分别将miR-137-3p mimics、NC与3′-UTR-WT和3′-UTR-Mut载体共转染HEK293T细胞,利用双荧光素酶报告试验检测miR-137-3p与MYC相关因子X(MAX)基因的靶向关系。将s...     

miR-23b-3p对3T3-L1前脂肪细胞增殖和成脂分化的影响

为探讨miR-23b-3p对3T3-L1前脂肪细胞增殖和成脂分化的影响,通过化学修饰的miR-23b-3p模拟物成功转入3T3-L1前脂肪细胞后,利用CCK-8法和流式细胞术检测过表达miR-23b-3p对3T3-L1前脂肪细胞增殖的影响;并通过实时荧光定量PCR和Western blot检测细胞周期基因CyclinD1和CDK4以及成脂标志基因PPARγ和FABP4的表达情况;油红O染色测定甘油三酯积累情况。结果显示,过表达miR-23b-3p抑制3T3-L1前脂肪细胞增殖,导致细胞G1期阻滞,CyclinD1、CDK4在mRNA和蛋白水平极显著下调;在3T3-L1前脂肪细胞成脂分化过程中,miR-23b-3p的表达水平上调;过表达miR-23b-3p促进3T3-L1前脂肪细胞甘油三酯积累,PPARγ、FABP4在mRNA和蛋白水平显著或极显著上调。结果表明,miR-23b-3p能够抑制3T3-L1前脂肪细胞增殖并促进其分化为成熟脂肪细胞。     

蛋氨酸对奶牛乳腺上皮细胞内乳脂合成相关基因和蛋白表达的影响

本试验旨在研究蛋氨酸(Met)对奶牛乳腺上皮细胞(BMECs)内乳脂合成相关基因和蛋白表达的影响,以探讨Met对乳脂合成的影响机理。将第3代BMECs随机分为6个处理(每个处理6个重复),培养液中Met浓度分别为0.13、0.26、0.39、0.52、0.65和0.78 mmol/L。在37℃、5%CO2条件下培养48 h后测定BMECs内甘油三酯(TG)的含量及乳脂合成相关基因和过氧化物酶体增殖物激活受体γ(PPARγ)与固醇调节元件结合蛋白1(SREBP1)蛋白的相对表达量。结果显示:Met浓度对BMECs内TG含量无显著影响(P0.05)。0.52~0.78 mmol/L Met处理BMECs内脂肪酸结合蛋白3(FABP3)、乙酰辅酶A羧化酶A(ACACA)和PPARγ基因的相对表达量均显著高于其他处理(P0.05)。BMECs内脂蛋白脂酶(LPL)基因的相对表达量以0.26~0.39 mmol/L Met处理较高,显著高于0.65~0.78 mmol/L Met处理(P0.05)。脂肪酸合成酶(FASN)基因的相对表达量以0.39~0.52 mmol/L Met处理较高,且0.52 mmol/L Met处理显著高于0.13~0.26 mmol/L和0.65~0.78 mmol/L Met处理(P0.05)。Met浓度可显著影响SREBP1和乙酰甘油磷酸脂酰转移酶6(AGPAT6)基因及SREBP1和PPARγ蛋白的表达(P0.05),均以0.26 mmol/L Met处理的相对表达量最高。结果表明,Met浓度影响BMECs内脂肪酸摄取、从头合成的基因的表达及乳脂合成调控因子PPARγ和SREBP1的基因和蛋白的表达,Met浓度为0.26~0.52 mmol/L时对BMECs内脂肪酸从头合成及长链脂肪酸摄取的促进效果较好。     

Plasma leptin and mRNA expression of lipogenesis and lipolysis-related factors in bovine adipose tissue around parturition

The objective was to study changes in plasma leptin concentration parallel to changes in the gene expression of lipogenic- and lipolytic-related genes in adipose tissue of dairy cows around parturition. Subcutaneous fat biopsies were taken from 27 dairy cows in week 8 antepartum (a.p.), on day 1 postpartum (p.p.) and in week 5 p.p. Blood samples were assayed for concentrations of leptin and non-esterified fatty acids (NEFA). Subcutaneous adipose tissue was analysed for mRNA abundance by real-time qRT-PCR encoding for leptin, adiponectin receptor 1 (AdipoR1), adiponectin receptor 2 (AdipoR2), hormones-sensitive lipase (HSL), perilipin (PLIN), lipoprotein lipase (LPL), acyl-CoA synthase long-chain family member 1 (ACSL1), acetyl-CoA carboxylase (ACC), fatty acid synthase (FASN) and glycerol-3-phosphate dehydrogenase 2 (GPD2). Body weight and body condition score of the cows were lower after parturition than before parturition. The calculated energy balance was negative in week 1 and 5 p.p., with higher negative energy balance in week 1 p.p. compared with that in week 5 p.p. On day 1 p.p., highest concentrations of NEFA (353.3 μmol/l) were detected compared with the other biopsy time-points (210.6 and 107.7 μmol/l, in week 8 a.p., and week 5 p.p. respectively). Reduced plasma concentrations of leptin during p.p. when compared with a.p. would favour increasing metabolic efficiency and energy conservation for mammary function and reconstitution of body reserves. Lower mRNA abundance of ACC and FASN expression on day 1 p.p. compared with other biopsy time-points suggests an attenuation of fatty acid synthesis in subcutaneous adipose tissue shortly after parturition. Gene expression of AdipoR1, AdipoR2, HSL, PLIN, LPL, ACSL1 and GPD2 was unchanged over time.     

Dietary conjugated linoleic acids increase intramuscular fat deposition and decrease subcutaneous fat deposition in Yellow Breed × Simmental cattle

This study was conducted to estimate the effect of dietary conjugated linoleic acids (CLA) on intramuscular and subcutaneous fat deposition in Yellow Breed × Simmental cattle. The experiment was conducted for 60 days. The results showed that the average backfat thickness, (testicles + kidney + pelvic) fat percentage and subcutaneous fat percentage in dietary CLA were significantly lower than in the control group, while intramuscular the fat percentage was significantly higher. Compared to the control group, the Longissimus muscle enzyme activities of lipoprotein lipase (LPL), fatty acid synthase (FAS) and acetyl‐coenzyme A carboxylase (ACC) in dietary CLA and the subcutaneous fat enzyme activities of LPL, hormone‐sensitive lipase (HSL) and carnitine palmitoyltransferase‐1 (CPT‐1) were significantly increased. Similarly, compared to the control group, the Longissimus muscle sterol regulatory element binding protein 1 (SREBP‐1), FAS, stearoyl‐coenzyme A desaturase (SCD), ACC, peroxisome proliferator‐activated receptor γ (PPARγ), heart fatty‐acid binding protein (H‐FABP) and LPL gene expression in dietary CLA were significant increased, as were the subcutaneous fat of PPARγ, H‐FABP, LPL, CPT‐1 and HSL in dietary CLA. These results indicated that dietary CLA increases IMF deposition mainly by the up‐regulation of lipogenic gene expression, while decreasing subcutaneous fat deposition mainly by the up‐regulation of lipolytic gene expression.     

Effects of different levels of protein supplementary diet on gene expressions related to intramuscular deposition in early‐weaned yaks

This study was conducted to estimate different levels of protein supplementary diet on gene expressions related to intramuscular deposition in early‐weaned yaks. Results showed that supplementary dietary protein significantly increased final weight, average daily gain (ADG), intramuscular fat (IMF), serum free fatty acid (FFA), total triglycerides, total cholesterol (Ch), low‐density lipoprotein cholesterol (LDL) and high‐density lipoprotein cholesterol (HDL) content. There was a quadratic response of ADG, IMF, FFA, Ch, HDL and LDL to dietary crude protein (CP) level. Lipoprotein lipase (LPL), fatty acid synthase (FAS) and acetyl‐CoA carboxylase (ACC) enzyme activities were significantly increased by supplementary dietary CP, while hormone‐sensitive lipase (HSL) and carnitine palmitoyltransferase‐1 (CPT‐1) activities were significantly decreased. LPL, ACC and FAS enzyme activities showed quadratic increase as dietary CP increased. Peroxisome proliferator‐activated receptor γ (PPARγ), LPL, FAS, sterol regulatory element binding protein 1 (SREBP‐1), ACC, stearoyl‐CoA desaturase (SCD) and heart fatty‐acid binding protein (H‐FABP) gene expression were significantly increased by supplementary dietary CP, while HSL and CPT‐1 gene expression were significantly decreased. PPARγ, LPL, SREBP‐1, ACC and H‐FABP gene expression showed quadratic increase as dietary CP increased. These results indicated that supplementary dietary protein increased IMF accumulation mainly to increased intramuscular lipogenic gene expression and decreased lipolytic gene expression.     

亮氨酸对奶牛乳腺上皮细胞内乳脂合成相关基因和蛋白表达的影响

本试验旨在研究亮氨酸(Leu)对泌乳奶牛乳腺上皮细胞(BMECs)内乳脂合成相关基因和蛋白表达的影响,以探讨Leu对乳脂合成的影响机理。将第3代BMECs随机分为6个处理,每个处理6个重复。6个处理培养液中Leu浓度分别为0.45、0.90、1.80、2.70、3.60和7.20 mmol/L,37℃、5%CO2培养48 h后测定BMECs内甘油三酯(TG)的含量及乳脂合成相关基因和过氧化物酶体增殖物激活受体γ(PPARγ)与固醇调节元件结合蛋白(SREBP1)蛋白的相对表达量。结果显示:Leu浓度对BMECs内TG含量无显著影响(P0.05)。适宜浓度的Leu显著促进脂肪酸合成酶(FASN)和乙酰辅酶A羧化酶A(ACACA)基因的表达(P0.05),FASN基因的相对表达量以1.80~2.70 mmol/L Leu处理、ACACA基因的相对表达量以1.80~7.20 mmol/L Leu处理较高。Leu浓度显著影响BMECs内SREBP1基因及蛋白表达(P0.05),以1.80 mmol/L Leu的促进效果最好。虽然Leu显著抑制BMECs内脂肪酸结合蛋白3(FABP3)、脂蛋白脂酶(LPL)、乙酰甘油磷酸脂酰转移酶6(AGPAT6)、线粒体甘油-3-磷酸酰基转移酶(GPAM)和嗜乳脂蛋白亚家族1成员1(BTN1A1)基因的表达(P0.05),但只有高浓度(3.60~7.20 mmol/L)的Leu抑制作用较大。综合来看,Leu浓度影响BMECs乳脂合成相关基因及PPARγ和SREBP1蛋白的表达。Leu浓度为1.80~2.70 mmol/L时,对脂肪酸从头合成相关基因及调控因子SREBP1蛋白表达的促进效果较好,对TG合成及脂滴形成相关基因表达的抑制作用较小。     

Effects of dietary energy level on lipid metabolism‐related gene expression in subcutaneous adipose tissue of Yellow breed × Simmental cattle

This study was conducted to estimate the effect of dietary energy level on lipid metabolism‐related gene expression of subcutaneous adipose tissue in Yellow breed × Simmental cattle. The experiment was conducted for 60 days. The results showed that final weight, average daily gain, average backfat thickness, (testicles + kidney + pelvic) fat percentage and subcutaneous fat percentage in the high and medium energy groups were significantly higher than in the low‐energy group but that the feed conversion ratio was significantly lower. The glucose, triglycerides, cholesterol, high‐density lipoprotein and low‐density lipoprotein in the high‐energy group were significantly higher than in the low‐energy group. With dietary energy increasing the activities of lipoprotein lipase (LPL), fatty acid synthase (FAS) and acetyl‐CoA carboxylase (ACC) significantly increased, whereas hormone‐sensitive lipase (HSL) and carnitine palmitoyltransferase‐1 (CPT‐1) significantly diminished. Peroxisome proliferator‐activated receptor γ (PPARγ), LPL, FAS, sterol regulatory element binding protein 1 (SREBP‐1), ACC, stearoyl‐CoA desaturase (SCD) and adipocyte‐fatty acid binding proteins (A‐FABP) gene expression were significantly increased by dietary energy increasing, and HSL and CPT‐1 gene expression were significantly decreased. These results indicated that with dietary energy increasing, the subcutaneous fat accumulation mainly increased due to adipose tissue lipogenic gene expression and decreased lipolytic gene expression.     

抑制剂T0070907对鸡PPARγ基因表达影响的研究

为了验证过氧化物酶体增殖物激活受体(PPAR)γ选择性抑制剂T0070907对鸡PPARγ基因表达的促进作用,本研究利用荧光定量PCR检测了不同浓度T0070907对鸡成纤维细胞(DF-1细胞)中PPARγ基因mRNA转录水平的影响,结果显示,随着T0070907浓度的增加,鸡PPARγ基因的表达量逐渐升高,并且在T0070907浓度为5μmol/L时极显著高于对照组(p<0.01);利用western blot检测了T0070907对PPARγ蛋白表达的影响,结果显示,5μmol/L的T0070907对DF-1细胞中PPARγ2蛋白的表达有一定的促进作用;利用双荧光素酶报告基因技术检测了不同浓度T0070907对PPRE报告基因活性的影响,结果显示,随着T0070907浓度的增加,DF-1细胞中PPRE报告基因活性逐渐增强,并且在T0070907浓度为0.5μmol/L时该报告基因活性显著高于对照组(p<0.05),当T0070907浓度为2μmol/L、5μmol/L时,与对照组之间的差异达到极显著水平(p<0.01);利用双荧光素酶报告基因技术检测了T0070907和罗格列酮(Rosi)对PPRE报告基因活性的影响,结果显示,单独添加T0070907或Rosi均可显著增强PPRE报告基因活性(p<0.05),同时,添加T0070907并不能降低Rosi对PPRE报告基因活性的促进作用。本研究结果表明,作为PPARγ抑制剂的T0070907对鸡PPARγ基因的mRNA的转录水平、蛋白表达及其蛋白活性均具有促进作用,推测与哺乳动物不同,鸡PPARγ可能具有其独特的表达方式和调控机制。本研究结果对完善PPARγ抑制剂在生理学及药理学上的研究、为PPARγ功能研究选择准确的拮抗剂、预防和治疗炎症相关疾病等方面具有重要意义。     

牛乳腺脂肪合成关键酶基因在乳汁体细胞中的表达研究

为了阐明乳脂合成的影响因素及其内在分子机理,为反刍动物原料乳的优化,特别是为乳脂肪的营养调控和遗传改良提供理论依据。本试验以奶牛初乳、常乳和末乳中的乳汁体细胞为研究对象,以看家基因GAPDH为内参,对初乳、常乳和末乳中LPL、CD36、VLDLR、ACSS2、ACSL1、FABP3、ACC、FASN、SCD、ADFP、XDH和BTN1A1 mRNA进行半定量RT-PCR分析。结果发现,LPL、CD36、VLDLR、ACSS2、ACSL1、FABP3、SCD、AD-FP、XDH和BTN1A1 mRNA在初乳、常乳和末乳中均有表达,而ACC和FASNmRNA只在初乳中表达,常乳和末乳中均不表达;半定量结果表明,与初乳相比,常乳和末乳中LPL、CD36、VLDLR、ACSS2、ACSL1、FABP3、SCD、ADFP、XDH和BTN1A1 mRNA转录水平显著降低(P<0.05),且常乳与末乳间差异不显著(P>0.05)。研究结果提示初乳期乳腺脂肪合成能力明显高于常乳和末乳期乳腺,且脂肪合成关键酶基因的表达与细胞内脂转运和代谢的生理变化有关。