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1.
为阐明miR-128a在大鼠前体脂肪细胞分化过程中的功能,本实验检测了大鼠(Rattus norvegicus)前体脂肪细胞成脂分化过程中miR-128a的表达,明确其在分化过程中的表达趋势;构建miR-128a的腺病毒过表达载体并侵染大鼠前体脂肪细胞,随后采用Real-time PCR和Western blot分别在mRNA和蛋白水平检测了成脂标记基因过氧化物酶体增生物激活受体γ(peroxisome proliferator-activated receptor gamma,PPARγ)和脂肪酸结合蛋白2(adipocyte protein 2,aP2)的表达;过表达miR-128a的大鼠前体脂肪细胞在第10天进行油红O染色,从形态学上观察成脂分化情况.结果显示,miR-128a的表达量在脂肪细胞诱导分化第二天降到最低点,随后维持在第0天的水平.在过表达miR-128a后,大鼠前体脂肪细胞成脂标记基因PPARγ和aP2的蛋白表达量与对照相比显著下降,脂滴明显少于对照组.实验结果表明:在大鼠前体脂肪细胞中过表达miR-128a能够抑制前体脂肪细胞的分化;并且通过PPARγ mRNA和蛋白水平的差异性变化,结合miRNA的作用机理,推测PPARγ有可能是miR-128a的靶基因.本实验也为研究miR-128a在脂肪细胞分化中发挥作用的机理提供了理论基础.  相似文献   

2.
抵抗素对肌体脂肪代谢和能量平衡起重要调节作用.为了研究抵抗素对猪原代前脂肪细胞增殖与分化的影响,本研究从1日龄仔猪皮下脂肪组织分离前脂肪细胞,分别培养于含有0、50、100、150和200μg/L重组抵抗素的DMEM/F12培养基,根据细胞形态、甘油三酯含量及脂蛋白脂酶活性的变化检测前脂肪细胞的增殖与分化情况.结果表明,在0~100μg/L范围内,随着培养液中抵抗素浓度的增加,抵抗素能显著促进猪前脂肪细胞增殖,细胞内脂蛋白脂酶活性显著增强;当培养液中抵抗素浓度增加至100~200μg/L时,猪前脂肪细胞增殖逐渐变弱,分化作用显著增强,甘油三酯合成代谢及细胞内脂肪滴聚集增加.研究结果提示抵抗素对猪前脂肪细胞生长具有双重作用.  相似文献   

3.
为研究颗粒体蛋白前体(granulin,GRN)在脂肪细胞发育过程中的作用,本实验构建了GRN短发夹RNA(short hairpin RNA,shRNA)慢病毒干扰载体,包装并感染猪前体脂肪细胞,采用油红O染色、油红O提取比色法检测猪前体脂肪细胞分化情况,采用Real-time PCR法检测成脂关键基因mRNA的表达变化情况。结果显示,GRN慢病毒干扰载体病毒滴度在5×107TU/mL以上,病毒感染前体脂肪细胞后显著降低了GRN的表达,shRNA2干扰效率最高,达到76%,沉默GRN后能够促进猪前体脂肪细胞分化;脂肪细胞分化标志基因过氧化物酶体增殖物激活受体γ(PPARγ)、固醇调节原件结合蛋白(SREBP-1c)、脂肪细胞型脂肪酸结合蛋白(ap2)和脂蛋白酯酶(LPL)基因mRNA表达量均升高。结果表明,降低GRN基因表达促进了猪前体脂肪细胞分化,揭示GRN在猪前体脂肪细胞分化过程中可能起到抑制作用。  相似文献   

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5.
本研究从中国荷斯坦新生公犊的脂肪组织中分离培养前脂肪细胞,体外诱导分化9 d后,细胞变圆出现大量脂滴成为脂肪细胞,伴随着前脂肪细胞标志基因前脂肪细胞因子-1(preadipocyte factor-1,Pref-1)的表达消失和脂肪细胞标志基因过氧化物酶体增殖物激活受体-γ(peroxisome proliferator-activated receptor-γ,PPAR-γ)mRNA高丰度表达.利用半定量RT-PCR技术研究胰岛素对脂联素mRNA表达水平的影响,发现1 nmol/L胰岛素对脂联素mRNA的表达水平没有影响(p>0.05),10 nmol/L、100 nmol/L和1000 nmol/L胰岛素分别能显著抑制脂联素mRNA 48.7%、61.4%和61.9%的表达(P<0.05).进一步研究发现,100 nmol/L胰岛素处理脂肪细胞24 h内呈时间依赖性抑制脂联素mRNA的表达,这种抑制效应随胰岛素的除去脂联素的转录水平24 h后恢复到对照水平,用LY294002抑制磷脂酰肌醇-3激酶(phosphatidylinositol-3 kinase,PI3K/Akt)信号通路后,胰岛素对脂联素的转录没有影响.结果提示,体外胰岛素在脂肪细胞中能通过PI3K/Akt信号通路可逆性抑制脂联素mRNA的表达.  相似文献   

6.
成熟脂肪去分化技术可为研究脂肪细胞分化提供均一的前体脂肪细胞。本研究分离培养了猪成熟脂肪细胞,并去分化为前体脂肪细胞。本实验采用Ⅱ胶原酶消化后离心分离1~3日龄仔猪(Susscrofa)皮下脂肪组织,天花板法培养获得成熟脂肪细胞。显微镜下观察脂肪细胞去分化形态学变化,并在成脂诱导培养液的作用下诱导再分化。采用油红O染色法检测分化不同时期细胞脂滴聚集效率,脂滴的累积随诱导的进行不断增加。RT-PCR检测成熟脂肪细胞标志基因过氧化物酶体增殖物活化受体(PPARγ)和和脂肪酸结合蛋白4(FABP4)的mRNA相对表达量,分化早期基因表达水平较低,其表达水平在分化过程中持续增高,在分化后期PPARγ相对表达量与诱导分化前增加了2.8倍,FABP4增加了约62倍(差异显著P<0.05)。说明去分化获得的前体脂肪细胞在成脂诱导培养液作用下,可有效地分化为成熟脂肪细胞。本研究优化了猪成熟脂肪细胞分离和培养体系,并通过去分化获得具有再分化能力的前体脂肪细胞,为进一步深入研究猪脂肪细胞分化与代谢提供技术平台。  相似文献   

7.
猪肌内前体脂肪细胞的体外培养   总被引:2,自引:0,他引:2  
本研究建立了猪肌内前体脂肪细胞的体外培养模型,以期为更深入研究猪肌内脂肪代谢提供新的实验方法。实验采集出生5d仔猪的背最长肌组织,Ⅱ型胶原酶消化2h后400目筛网过滤,然后1500r/min离心,沉淀用含10%胎牛血清的DMEM/F12培养基(完全培养基)重悬后差速贴壁2h,弃去原有培养基,加入新的含10%胎牛血清的DMEM/F12培养基(完全培养基)进行培养。细胞经传代且完全融合48h后,在完全培养基中添加0.5mmol/L3-异丁基-1-甲基黄嘌呤(IBMX),1μmol/L地塞米松(DEX),10mg/L胰岛素(INS)进行诱导培养48h,再换以含10mg/L胰岛素的完全培养基培养48h,最后换完全培养基继续培养,直至90%的细胞出现脂滴。培养结果:细胞贴壁生长,呈短梭状或棱形,经诱导培养后细胞充脂率高。经形态学观察、生长曲线及油红O脂肪染色法鉴定,证明是肌内前体脂肪细胞。普通PCR及实时荧光定量PCR均检测到了脂联素基因的表达。本研究通过差速贴壁法成功培养了猪肌内前体脂肪细胞,并通过诱导培养重现了其分化、成熟的全过程。  相似文献   

8.
以分离新生牛腹股沟白色脂肪组织的前脂肪细胞进行原代培养为基础,采用MTT比色法和油红O提取比色法研究表皮生长因子(epidermal growth factor,EGF)对牛前脂肪细胞增殖及分化的影响,同时通过半定量RT-PCR检测不同浓度EGF处理细胞第8天时对分化标志基因脂蛋白酯酶(lipoprotein lipase,LPL)、过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)、脂肪细胞脂肪酸结合蛋白(adipocyte fatty-acid-binding protein,A-FABP)mRNA表达的影响.结果表明,10 ng/mL EGF能极显著地促进前脂肪细胞的增殖(P<0.01),在分化诱导后添加不同浓度的EGF在第8天均可促进脂肪细胞的分化,并能促进脂肪细胞分化标志基因LPL、PPARγ和A-FABPmRNA的表达.EGF可以促进牛前脂肪细胞的增殖和分化.  相似文献   

9.
为探讨类胰岛素样生长因子-Ⅰ(IGF-Ⅰ)、生长激素(GH)和共轭亚油酸(CLA)对不同部位来源脂肪前体细胞的增殖和分化程度的影响,以大鼠(Rattus norveaicus)为实验模型,分别从附睾及皮下脂肪组织分离得到脂肪前体细胞,并在不同浓度的IGF-Ⅰ、GH和CLA处理后,用MTT法检测脂肪前体细胞的增殖,用油红O染色法检测脂肪前体细胞的分化聚脂程度。实验结果表明,各剂量IGF-Ⅰ和CLA均能够显著地促进大鼠附睾及皮下脂肪前体细胞的增殖与分化,但GH对大鼠附睾及皮下脂肪前体细胞的增殖与分化均无明显作用。为进一步观察IGF-Ⅰ和CLA对皮下脂肪组织的作用机制,实验采用半定量RT-PCR法检测细胞中PPARγ和C/EBPα基因表达水平,结果发现,100ng/mL IGF-I可显著上调大鼠脂肪前体细胞中PPARγ与C/EBPα基因表达水平;48ng/m LGH和100μmol/L CLA可显著促进PPARγ基因表达,但对C/EBPα mRNA表达无显著影响。结果示IGF-I可能主要通过上调PPARγ与C/EBPα基因的高水平表达进而促进大鼠脂肪前体细胞的分化,而CLA对脂肪前体细胞的作用在上调PPARγ的表达的同时,还作为PPARγ的配体激活该受体而发挥作用。  相似文献   

10.
采用semi-qRT-PCR、细胞转染、Hoechst 33342和吖啶橙(AO)荧光染色、流式细胞术等方法,检测体外培养的猪前体脂肪细胞经维甲酸X受体α(RXRα)的配体9顺式维甲酸(9-cis Retinoic acid,9-cisRA)处理、转染增强型绿色荧光蛋R(pEn-hanced green fluorescent proteins C2)-RXRα(pEGFPC2-RXRα)重组质粒和化学合成的RXRa-小分子干扰RNA (small interferingRNA)(RXRα-siRNA)后细胞凋亡的变化.结果表明.猪前体脂肪细胞发牛凋亡的形态学变化为细胞首先体积缩小.细胞浆凝缩,染色质逐渐凝集.细胞核固缩呈均一的致密物,进而断裂,胞膜仍完整,然后胞膜小断出芽、脱落.最后细胞变成数个大小不等的由膜包裹的凋亡小体;10nmol/L 9-cisRA组与对照组相比,凋亡率显著降低(P相似文献   

11.
Cinnamon (Cinnamomum verum) has been widely used in spices, flavoring agents, and preservatives. Cinnamon polyphenol extract (CPE) may be important in the alleviation of chronic diseases, but the molecular evidence is not substantial. Tristetraprolin (TTP) family proteins have anti-inflammatory effects through the destabilization of pro-inflammatory mRNAs. TTP expression is reduced in fats of obese people with metabolic syndrome and brains of suicide victims. This study used quantitative real-time PCR to explore the effects of CPE on the regulation of TTP, VEGF, and related gene expression in mouse 3T3-L1 adipocytes. CPE (100 μg/mL) increased TTP mRNA levels by up to 10-fold, and this stimulation was sustained over 16 h. The levels of VEGF mRNA, a putative target of TTP, were decreased 40-50% by CPE. It also affected the expression of other genes coding for ZFP36L1 and ZFP36L3 (TTP homologues), GM-CSF, COX2, IL6, APP, G-CSF, and PAI1. This study demonstrated that CPE rapidly induces TTP mRNA and reduces VEGF mRNA and affects the expression of a number of other genes in the cultured adipocytes.  相似文献   

12.
Cinnamaldehyde (CA), one of the active components of cinnamon, has been known to exert several pharmacological effects such as anti-inflammatory, antioxidant, antitumor, and antidiabetic activities. However, its antiobesity effect has not been reported yet. This study investigated the antidifferentiation effect of CA on 3T3-L1 preadipocytes, and the antiobesity activity of CA was further explored using high-fat-diet-induced obese ICR mice. During 3T3-L1 preadipocytes were differentiated into adipocytes, 10-40 μM CA was treated and lipid contents were quantified by Oil Red O staining, along with changes in the expression of genes and proteins associated with adipocyte differentiation and adipogenesis. It was found that CA significantly reduced lipid accumulation and down-regulated the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding proteins α (C/EBPα), and sterol regulatory element-binding protein 1 (SREBP1) in concentration-dependent manners. Moreover, CA markedly up-regulated AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC), and these effects were blunted in the presence of AMPK inhibitor, compound C. In the animal study, weight gains, insulin resistance index, plasma triglyceride (TG), nonesterified fatty acid (NEFA), and cholesterol levels in the 40 mg/kg of CA-administered group were significantly decreased by 67.3, 55, 39, 31, and 23%, respectively, when compared to the high-fat diet control group. In summary, these results suggest that CA exerts antiadipogenic effects through modulation of the PPAR-γ and AMPK signaling pathways.  相似文献   

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Saponarin, a flavonoid found in young green barley leaves, possesses potent antioxidant activities, which are determined by its inhibition of malonaldehyde (MA) formation from various lipids oxidized by UV light or Fenton's reagent. Lipids used were squalene, ethyl linoleate, ethyl linolenate, ethyl arachidonate, octadecatetraenoic acid (ODTA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), cod liver oil, lecithin I, lecithin II, and blood plasma. The addition of saponarin inhibited the formation of MA from squalene upon UV irradiation at the level of 2 μmol/mL by almost 100%, whereas BHT inhibited its formation by 75% at the same level. Saponarin showed potent antioxidant activity toward fatty acid ethyl esters at levels >100 μg/mL. Saponarin inhibited MA formation in ODTA by 60%, in EPA by 50%, and in DHA by 43% at the level of 15 μmol/mL. Saponarin exhibited strong antioxidant activities with dose-response levels toward cod liver oil and lipoproteins (lecithins I and II), higher than those of α-tocopherol. A mixture of saponarin/lutonarin (4.5:1, w/w) inhibited MA formation appreciably from all lipids tested with dose response. This mixture exhibited highest effect toward cod liver oil (86%), followed by DHA, lecithin II, blood plasma, EPA, and lecithin I. Supplementation of young green barley leaves containing saponarin should be beneficial to health and may prevent diseases caused by oxidative damage such as various cancers, inflammations, and cardiovascular diseases.  相似文献   

15.
控制肉鸡脂肪过多沉积是肉鸡生产中亟待解决的问题。脱氢表雄酮(dehydroepiandrosterone,DHEA)是人体分泌最为丰富的肾上腺类固醇激素,可经由类固醇激素受体介导发挥生理功能,降低机体生脂能力。本研究以鸡胚原代肝细胞为研究对象,选用含DHEA终浓度为0(对照)、0.01、0.1、1.0、10和100μmol/L的培养液孵育肝细胞20min后收集细胞,放射免疫测定法(RIA)检测胞内cAMP水平。结果发现,0.1~100μmol/L DHEA孵育肝细胞均可显著提高胞内cAMP水平(P<0.05),其中0.1μmol/L DHEA效果最为显著(P<0.01)。0.1μmol/L DHEA孵育肝细胞20min或1h后收集细胞,RIA法分别检测胞内腺苷酸环化酶(adenylate cyclase,AC)和磷酸二酯酶(phosphodiesterase,PDE)活性,(γ-32P)ATP掺入法测定cAMP依赖性蛋白激酶A(protein kinase A,PKA)活性,Western blot法测定cAMP反应元件结合蛋白(cAMP-response element binding protein,CREB)磷酸化水平。结果显示,0.1μmol/L DHEA孵育肝细胞20min可显著降低胞内PDE活性(P<0.05),提高PKA活性(P<0.05),但对AC活性无显著性影响(P>0.05)。0.1μmol/L DHEA处理肝细胞1h可显著提高CREB蛋白磷酸化水平(P<0.05),且这种效应可被PKA抑制剂阻断(P>0.05)。本研究结果提示,DHEA调控肉鸡肝脏脂肪代谢,降低脂肪沉积的机制可能与激活胞内cAMP/PKA信号系统,活化转录因子CREB有关。  相似文献   

16.
Three triterpenic acids, oleanolic acid, ursolic acid and maslinic acid, at 2 or 4 μmol/L were used to study their antiangiogenic potential in human liver cancer Hep3B, Huh7 and HA22T cell lines. The effects of these compounds upon the level and/or expression of hypoxia-inducible factor (HIF)-1α, basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), interleukin (IL)-8, urokinase plasminogen activator (uPA), reactive oxygen species (ROS), nitric oxide (NO) and cell invasion and migration were examined. Results showed that these triterpenic acids at 4 μmol/L significantly suppressed HIF-1α expression in three cell lines (P < 0.05); and these compounds at test doses failed to affect bFGF expression (P > 0.05). Three triterpenic acids dose-dependently decreased production and expression of VEGF and IL-8, retained glutathione level, lowered ROS and NO levels, and declined cell invasion and migration in test cell lines (P < 0.05). These compounds also dose-dependently reduced uPA production and expression in Hep3B and Huh7 cell lines (P < 0.05); but these agents only at 4 μmol/L significantly suppressed uPA production and expression in HA22T cells (P < 0.05). These findings suggest that these triterpenic acids are potent antiangiogenic agents to retard invasion and migration in liver cancer cells.  相似文献   

17.
猪作为重要的疾病模型动物,目前猪诱导多能干细胞(iPS 细胞)已有建系,但是细胞的冻存和传代的效率较低,影响后续的实验研究。Rho 相关蛋白激酶(ROCK)抑制剂 Y-27632 可提高人胚胎干细胞的解冻存活率,促进其克隆形成。本实验以猪(Sus scrofa)iPS 细胞为研究对象,通过在猪 iPS 细胞冻存和解冻过程中添加Y-27632,发现其可以减少猪 iPS 细胞在冻存和解冻复苏过程中的凋亡。在细胞的传代过程中,使用 Y-27632 可以促进猪 iPS 细胞的贴壁和克隆形成。虽然高浓度 Y-27632 会对猪 iPS 克隆的形态产生一定的影响,但并未影响细胞的碱性磷酸酶(AP)活性和多能性基因 Oct4、Sox2 和 Nanog 的表达水平。最后将转座子报告质粒 PB[Act-RFP]DS 导入猪 iPS 细胞中,经流式筛选后得到的带有红色荧光的细胞,并将其注射于猪孤雌胚胎中进行发育能力检测,发现 Y-27632 的处理能减少细胞在流式筛选和胚胎注射中的凋亡,促进其在胚胎内的嵌合发育。研究结果说明,ROCK 抑制剂 Y-27632 可以提高猪 iPS 细胞冻存和传代的效率,促进其在胚胎中的嵌合。该研究有助于猪 iPS 细胞及其他多能干细胞的保存,传代和筛选等相关研究。  相似文献   

18.
This paper describes the results of a series of experiments designed to identify the relative importance of various factors which modify the responses of a sensitive species to ozone. The experiments were conducted in a closed chamber exposure system, enabling clover plants (Trifolium subterraneum L. cv Geraldton) to be exposed to ozone doses ranging from 0 to 1800 ppb.h, accumulated over 40 ppb (AOT40), for 7 h d?1, over 1 to 3 days. Microclimatic conditions during exposure ranged from 80 to 460 μmol m?2 s?1 photosynthetically active radiation (PAR), 26 to 61 percent relative humidity (%RJH) and 16 to 36 °C temperature. No clear dose response relationships were established for 1, 2 or 3 day exposures due to the influence of microclimatic and other factors during exposure. Artificial Neural Networks were used as a tool to identify patterns within the dose response data set and to clarify the effects of various microclimatic and dose topography responses, during multiple day exposures. Analysis of the trained neural network revealed that AOT40 on individual exposure days was the most important influences PAR on the first and third days of exposure, the mean relative humidity and the mean temperature for all days also had strong influences. Leaf age also had an influence but this was weaker. This paper describes these results in relation to the influences acting upon the plant and how these affect ozone uptake and resulting ozone injury.  相似文献   

19.
Analysis of Concord grape juice by HPLC with ESI-MS(n), PDA, and fluorescence detection resulted in the identification and quantification of 60 flavonoids and related phenolic compounds, which were present at an overall concentration of 1508 ± 31 μmol/L. A total of 25 anthocyanins were detected, which were mono- and di-O-glucosides, O-acetylglucosides, O-p-coumaroyl-O-diglucosides, and O-p-coumaroylglucosides of delphinidin, cyanidin, petunidin, peonidin, and malvidin. The anthocyanins represented 46% of the total phenolic content of the juice (680 μmol/L). Tartaric esters of hydroxycinnamic acids, namely, trans-caftaric and trans-coutaric acids, and to a lesser extent trans-fertaric acid accounted for 29% of the phenolic content, with a total concentration of 444 μmol/L, of which 85% comprised trans-caftaric acid. Free hydroxycinnamic acids were also quantified but contributed to <1% of the total phenolic content (8.4 μmol/L). The other groups of polyphenolic compounds present in the juice, accounting for 24% of the total, comprised monomeric and oligomeric units of (epi)catechin and (epi)gallocatechin (248 μmol/L), flavonols (76 μmol/L), gallic acid (51 μmol/L), and trans-resveratrol (1.5 μmol/L). The bioavailability of the (poly)phenolic compounds in 350 mL of juice was investigated following acute intake by healthy volunteers. Plasma and urine were collected over 0-24 h and analyzed for parent compounds and metabolites. In total, 41 compounds, principally metabolites, were identified.  相似文献   

20.
Currently, at the beginning of the 21st century, obesity has become the leading metabolic disease in the world. It is a serious health problem in industrialized countries. Previous research has suggested that decreased preadipocyte differentiation and proliferation and decreased lipogenesis are mechanisms to reduce obesity. In the present study, the effects of capsaicin on the induction of apoptosis and inhibition of lipid accumulation in 3T3-L1 preadipocytes and adipocytes were investigated. The results demonstrated that capsaicin decreased cell population growth of 3T3-L1 preadipocytes, assessed with the MTT assay. Flow cytometric analysis of 3T3-L1 preadipocytes exposed to capsaicin showed that apoptotic cells increased in a time- and dose-dependent manner. Treatment with capsaicin decreased the number of normal cells and increased the number of early apoptotic and late apoptotic cells in a dose-dependent manner. The treatment of cells with capsaicin caused the loss of mitochondria membrane potential (delta psi m). The induction of apoptosis in 3T3-L1 preadipocytes by capsaicin was mediated through the activation of caspase-3, Bax, and Bak, and then through the cleavage of PARP and the down-regulation of Bcl-2. Moreover, capsaicin significantly decreased the amount of intracellular triglycerides and glycerol-3-phosphate dehydrogenase (GPDH) activity in 3T3-L1 adipocytes. Capsaicin also inhibited the expression of PPARgamma, C/EBPalpha, and leptin, but induced up-regulation of adiponectin at the protein level. These results demonstrate that capsaicin efficiently induces apoptosis and inhibits adipogenesis in 3T3-L1 preadipocytes and adipocytes.  相似文献   

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