3T3-L1前脂肪细胞分化过程中miRNAs基因的表达变化

目的:探讨3T3-L1前脂肪细胞诱导分化过程中miRNAs基因的表达变化。方法:运用经典的"激素鸡尾酒"法建立3T3-L1前脂肪细胞分化模型。采用实时定量聚合酶链式反应方法检测不同时相点(0d、2h、2d、4d)细胞分化相关标志物的表达和20种miRNAs的表达变化,采用生物信息学方法对变化显著的miRNAs进行靶基因预测。结果:成功建立3T3-L1前脂肪细胞分化模型。不同时相点细胞分化相关标志物基因水平提示3T3-L1前脂肪细胞分化为脂肪细胞。20种miRNAs中以miR-126、miR-214、miR-320、miR-351的表达最为显著。靶基因预测结果显示,miR-126靶基因有影响细胞增殖的转录因子Crk、代谢相关基因Irs1等;miR-214靶基因有转录因子Zbtb20、Kpna1等;miR-320靶基因有影响代谢相关基因Igf2bp3、Gxylt1等;miR-351靶基因有Myt1、Mcl1、Bmf等。结论:miR-126、miR-214、miR-320、miR-351可通过影响基因转录及细胞代谢水平,从而对3T3-L1前脂肪细胞分化发挥作用,为开发治疗肥胖等疾病的新药提供了新的研究思路。     

荭草素抑制3T3-L1前脂肪细胞分化及其改善胰岛素抵抗的作用研究

目的研究荭草素对3T3-L1前脂肪细胞分化及对脂肪细胞胰岛素抵抗的影响,并探讨其作用机制。方法传统鸡尾酒法诱导分化3T3-L1前脂肪细胞,MTT法检测荭草素对前脂肪细胞活力的影响,油红O染色法检测脂质积累,酶法检测细胞内甘油三酯(triglyceride,TG)的含量。地塞米松诱导成熟的脂肪细胞,建立胰岛素抵抗模型,荧光标记2-脱氧葡萄糖(2-[N-(7-nitrobenz-2-oxa-1,3-diaxol-4-yl)amino]-2-deoxyglucose,2-NBDG)摄入法观察脂肪细胞对葡萄糖的摄取能力;Western blot检测腺苷酸活化蛋白激酶(adenosine monophosphate activated protein kinase,AMPK)、乙酰辅酶A羧化酶(acetyl Co A carboxylase,ACC)的磷酸化水平及葡萄糖转运体4(glucose transporter type 4,GLUT4)的表达水平,免疫荧光法检测GLUT4的向膜转位能力。结果荭草素可浓度依赖性地减少细胞脂滴的积累及细胞内TG的含量,但对细胞活力无明显的影响(P>0.05)。胰岛素抵抗状态下,荭草素明显增加脂肪细胞对2-NBDG的摄取(P<0.05),明显上调AMPK、ACC的磷酸化水平(P<0.05),促进GLUT4的向膜转位及表达。结论荭草素抑制前脂肪细胞的分化,同时,荭草素通过上调AMPK/GLUT4信号途径相关蛋白的表达,促进了细胞对葡萄糖的摄取,达到改善胰岛素抵抗的作用。     

小鼠3T3-L1前脂肪细胞培养与诱导分化方法的建立

目的建立小鼠3T3-L1前脂肪细胞的培养及诱导分化为成熟脂肪细胞的方法。方法使用含10%胎牛血清（FBS）的高糖达氏修正伊氏培养基（DMEM）-F12液体培养基在体积分数5%二氧化碳（CO2）、37℃条件下常规培养3T3-L1细胞,2~3 d换液1次;诱导分化培养基Ⅰ培养2 d,诱导分化培养基Ⅱ培养2 d;基础培养基培养4~6 d,1~2 d换液1次。结果小鼠3T3-L1前脂肪细胞状态良好,成铺路石状生长,布满培养瓶底,3 d传代1次。90%以上细胞诱导分化成功,细胞呈圆形,有大量酯滴聚集,油红O染色呈橘红色。结论建立了小鼠3T3-L1前脂肪细胞的培养方法和诱导分化方法,为肥胖相关药物研究奠定了方法基础。     

五甲基槲皮素对3T3-L1前脂肪细胞分化及对脂肪细胞PPAR-γ和脂联素mRNA表达的影响

目的：比较PMQ和罗格列酮3T3-L1前脂肪细胞分化及脂肪细胞PPA脚和脂联素mRNA表达的影响。方法：待细胞融合2天后，加用胰岛素诱导3T3-L1前脂肪细胞分化。分化的过程中全程分别给予0.1，0.3，1,3，10，30，100μM的五甲基槲皮素和1，10μM的罗格列酮。诱导分化第12天，油红O染色，异丙醇洗脱后，570nm波长测值，     

板蓝根水提物对3T3-L1前脂肪细胞增殖和分化的影响

目的探讨板蓝根水提物(water extract of Radix Isatidis,WERI)对3T3-L1前脂肪细胞增殖分化的影响及其作用机制。方法体外培养3T3-L1前脂肪细胞,MTT法和流式细胞技术检测WERI对细胞增殖的影响;鸡尾酒诱导剂诱导3T3-L1前脂肪细胞,油红O染色和比色分析法观察WERI对前脂肪细胞分化及脂肪积累的影响;采用RT-PCR检测脂肪细胞的过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)及CCAAT/增强子结合蛋白α(CCAAT/enhancer-binding proteinα,C/EBPα)mRNA的表达;Western blot法检测PPARγ及C/EBPα蛋白表达。结果WERI在一定浓度范围内能有效抑制3T3-L1前脂肪细胞增殖,同时细胞周期呈现G_0/G_1向S期阻滞;与空白组相比,用不同浓度的WERI处理后,3T3-L1前脂肪细胞的分化受到明显抑制,且细胞内脂滴生成量明显减少;PCR及Western blot结果显示,WERI还可以抑制脂肪细胞PPARγ和C/EBPα基因及蛋白的表达。结论 WERI具有抑制3T3-L1前脂肪细胞增殖作用,并可通过下调PPARγ和C/EBPαmRNA及蛋白表达来抑制细胞成脂分化。     

小檗碱对3T3-L1前脂肪细胞增殖和分化的影响

脂肪细胞的增多是由于前脂肪细胞的不断分化引起。小檗碱是中药黄连的成分，具有改善胰岛素抵抗、降低血糖和调节血脂紊乱的作用，可用于治疗2型糖尿病，但它是否参与脂肪细胞的增殖和分化过程，目前尚不清楚。本研究通过小檗碱干预小鼠前脂肪细胞观察其对该细胞增殖和分化的影响，为肥胖的2型糖尿病的治疗提供可能的途径。     

HDL对3T3-L1细胞葡萄糖转运的影响及其机制研究

目的探讨HDL对3T3-L1细胞葡萄糖转运的影响及其机制。方法通过对3T3-L1成纤维细胞的分化,培养符合实验要求的3T3-L1脂肪细胞。通过葡萄糖消耗实验和~3H标记的2-脱氧葡萄糖的摄取实验,研究HDL对葡萄糖转运的影响,应用RT-PCR和Western blot探讨其机制。结果 HDL可以促进3T3-L1脂肪细胞对葡萄糖的转运和摄取。3T3-L1脂肪细胞对葡萄糖的转运和摄取过程中,蛋白在RNA转录水平上没有增加,而是发生了AKT、AMPK蛋白的磷酸化。结论 HDL促进3T3-L1脂肪细胞对葡萄糖的摄取是通过AKT和AMPK两种途径来实现的。     

太子参提取物对3T3-L1前脂肪细胞分化的影响

目的 探索太子参提取物对3 T3-L1前脂肪细胞分化的影响.方法 采用超声提取法获得太子参乙醇提取物,再分别用石油醚、乙酸乙酯、水饱和正丁醇进行连续萃取,用得到的太子参各溶剂萃取层作用于3 T3-L1前脂肪细胞分化模型,以罗格列酮为阳性对照药,并通过油红O染色观察其对前脂肪细胞分化过程的影响.结果 太子参乙醇提取物及各极性溶剂萃取层在0.4μg·mL-1和0.8μg·mL-1两个浓度下均能在一定程度上促进前脂肪细胞的分化过程,而且乙酸乙酯萃取层活性最强.结论 太子参乙酸乙酯萃取层具有较好的促进3 T3-L1前脂肪细胞分化的活性.     

小鼠前脂肪细胞3T3-L1培养与四联诱导分化方法的探讨

摘要： 目的 改进小鼠前脂肪细胞 3T3-L1 的培养并诱导分化为成熟脂肪细胞的方法。方法 使用含有 10％胎牛血清 （FBS） 的高糖型 DMEM 液体培养基常规培养小鼠前脂肪细胞, 2~3 d 换液 1 次。细胞按诱导分化方式的不同分为三联诱导组和四联诱导组。三联诱导组诱导分化培养基Ⅰ成分为常规培养基基础上加用人胰岛素 10 mg/L, 1- 甲基-3-异丁基黄嘌呤 （IBMX）0.5 mmol/L, 地塞米松 （DEX） 1.0 μmol/L; 四联诱导组诱导分化培养基Ⅰ的成分为在三联诱导组基础上加入吲哚美辛 0.1 mmol/L。2 组均诱导分化培养基Ⅰ培养 2 d, 连续诱导 2 次后换用诱导分化培养基Ⅱ, 成分为： 高糖型 DMEM 培养基含 10 %胎牛血清、 100 U/mL 青霉素和 100 mg/L 链霉素混合液, 人胰岛素 10 mg/ L。培养 2 d, 连续诱导 2 次。倒置显微镜和油红 O 染色观察诱导前及诱导后 2 组细胞的形态变化。结果 小鼠前脂肪细胞 3T3-L1 状态良好, 呈现铺路石状生长, 均匀布满培养瓶底, 2 d 传代 1 次。四联诱导组诱导分化结果优于三联诱导组。三联诱导剂诱导前脂肪细胞后, 细胞形态并未发生明显变化。四联诱导剂诱导前脂肪细胞后, 可达到 90％以上的成熟脂肪细胞。成熟的脂肪细胞呈圆形, 有大量脂滴聚集, 油红 O 染色显现橘红色。结论 在三联诱导基础上加入吲哚美辛的四联诱导法可以更好地促进脂肪前体细胞分化。     

脂肪因子Apelin-13对3T3-L1脂肪细胞水通道蛋白7基因表达的影响

目的 探讨脂肪因子Apelin-13对3T3-L1脂肪细胞水通道蛋白7（AQP7）基因表达的影响.方法 体外培养3T3-L1脂肪细胞,以油红O染色鉴定为成熟脂肪细胞后,分为阴性对照组（无干预）,不同浓度（10^-9、10^-8、10^-7、10^-6nmol/L） Apelin-13干预组（均干预24 h）,阳性对照组（10^-5 nmol/L罗格列酮干预24 h）和10^-7 nmol/L Apelin-13干预不同时间（0、12、24、36、48 h）组.用反转录-聚合酶链反应检测各组细胞AQP7 mRNA表达水平.结果 阴性对照组、10^-9、10^-8、10^-7、10^-6 nmol/L Apelin-13和阳性对照组AQP7表达水平分别为（0.22±0.02）、（0.29±0.07）、（0.36±0.05）、（0.43±0.05）、（0.31±0.06）、（0.32±0.08）,阳性对照组与阴性对照组之间差异有统计学意义（P＜0.05）;与阴性对照组比较,10^-8、10^-7 nmol/L Apelin-13能明显刺激AQP7 mRNA表达（P ＜0.05）;10^-8、10^-7 nmol/L Apelin-13组与阳性对照组比较,10^-7 nmol/L Apelin-13能明显刺激AQP7 mRNA表达（P＜0.05）;10^-8、10^-7 nmol/L Apelin-13组间差异无统计学意义.在时间组中,10^-7 nmol/L Apelin-13的0、12、24、36、48 h各组灰度比值分别为（0.27±0.09）、（0.43±0.07）、（0.55±0.10）、（0.42±0.08）、（0.33±0.09）,12、24、36 h组AQP7 mRNA表达较0h组能明显刺激AQP7 mRNA表达（P＜0.05）,作用24 h表达最高;但12、24、36h3组之间AQP7mRNA表达差异无统计学意义.结论 Apelin-13在一定程度上能增加3T3-L1脂肪细胞AQP7 mRNA表达的水平,并分别以10^-7 nmol/L和24 h为最佳作用浓度和时间.     

Chemical constituents of Triticum aestivum and their effects on adipogenic differentiation of 3T3-L1 preadipocytes

Archives of Pharmacal Research - In this report, we investigated the anti-obesity effect of wheat sprouts and their component compounds. Twenty compounds (1–20) were isolated from Triticum...     

Glucocorticoid regulation of beta-adrenergic receptors in 3T3-L1 preadipocytes

Treatment of 3T3-L1 preadipocytes (fibroblasts) with 250 nM dexamethasone for 48 hr caused a doubling of total beta-adrenergic receptors and an increase in beta 2-adrenergic receptor subtype proportion from approximately 50% in controls to 85% in treated cells. The responses to epinephrine and norepinephrine in a whole cell cAMP accumulation assay reflected these changes. The effects of dexamethasone on beta-adrenergic receptors were mediated through the glucocorticoid receptor and were time and dose dependent with an EC50 of 2.77 +/- 0.73 nM for an increase in the proportion of beta 2-adrenergic receptors. The rank order of potency of steroids to effect these changes (betamethasone = dexamethasone greater than fludrocortisone greater than hydrocortisone = triamcinolone greater than aldosterone) correlated with their glucocorticoid potency. [3H]Dexamethasone binding to intact cells yielded a KD value of 3.47 +/- 0.38 nM for binding to the glucocorticoid receptor which correlated well with the EC50 for dexamethasone to alter beta-adrenergic receptors. Inhibition of [3H]dexamethasone binding by other steroids confirmed that the ability of steroids to regulate beta-adrenergic receptors correlated with the affinity of each compound for the 3T3-L1 glucocorticoid receptor. Progesterone, which can bind to the glucocorticoid receptor but has only weak agonist activity, competitively inhibited the ability of dexamethasone to alter beta-adrenergic receptors. Protein synthesis, RNA synthesis, and N-linked glycosylation appeared to be necessary for the change in receptor subtype expression and the increase in beta-adrenergic receptor number induced by dexamethasone. The present study suggests that regulation of beta-adrenergic receptor expression in 3T3-L1 preadipocytes by dexamethasone is a glucocorticoid-specific effect which may require gene activation.     

Effects of pine needle extract on differentiation of 3T3-L1 preadipocytes and obesity in high-fat diet fed rats

The present study examined the anti-obesity effects of pine needle extract (PNE) in 3T3-L1 preadipocytes and in vivo studies. PNE treatment suppressed both glycerol-3-phosphate dehydrogenase activity and expression of peroxisome proliferator-activated receptor (PPAR) gamma in cultured 3T3-L1 adipocytes. To investigate the effect of PNE on obesity in rats fed high-fat diet, four types of diet, which included a normal diet (ND), high-fat diet (HFD), ND+PNE, and HFD+PNE diets, were fed to the rats ad libitum for 6 weeks. The PNE supplement significantly decreased body weight gain and visceral fat mass compared to the HFD group. The total cholesterol, TG, and leptin levels in the plasma were significantly reduced by PNE supplementation compared with those of the HFD group. Histological findings in liver tissue showed that PNE supplementation alleviated steatosis induced by HFD. In conclusion, PNE treatment suppressed differentiation of 3T-L1 adipocytes, in part by down-regulating expression of PPAPgamma mRNA, and reduced adipose tissue mass, hyperlipidemia, and hepatic steatosis in obese rats fed HFD. Therefore, pine needle water extract may be considered for use in therapy to control obesity.     

Antiobesity effects of quercetin-rich onion peel extract on the differentiation of 3T3-L1 preadipocytes and the adipogenesis in high fat-fed rats

The aim of the present study was to examine the effect of quercetin-rich onion peel extract (OPE) on anti-differentiation in 3T3-L1 preadipocytes and the antiobesity in high-fat fed rats. We found that lipid accumulations and TG contents in 3T3-L1 cells were markedly suppressed by OPE. The mRNA levels of activating protein (AP2) were down-regulated and those of carnitine palmitoyl transferase-1 α (CPT-1α) and fatty acid binding protein 4 (FABP4) were up-regulated by 75 and 100 μg/ml OPE. Body weight, retroperitoneal and mesenteric fat weights of SD rats were significantly lower in the 8 week high fat (HF) diet + 0.72% OPE group than in the HF group. Peroxisome proliferator-activated receptor (PPAR)γ mRNA levels were down-regulated in the epididymal fat of OPE than those of control and HF, and significant down-regulation of CCAAT/enhancer binding protein (C/EBP)α mRNA levels in OPE was also observed than the control. The mRNA levels of CPT-1α and uncoupling protein-1 (UCP-1) were up-regulated by the OPE, while those of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) were down-regulated in HF and OPE groups compared to control group. These results suggest that quercentin-enriched OPE may have antiobesity effects by suppressing preadipocyte differentiation and inhibiting adipogenesis.     

Regulation of beta-adrenoceptor number and subtype in 3T3-L1 preadipocytes by sodium butyrate

In mouse 3T3-L1 preadipocytes, the glucocorticoid dexamethasone has been shown to promote a switch in beta-adrenoceptor subtype expression from beta 1 to beta 2 and to increase the total number of beta-adrenoceptors. The present study demonstrates that sodium butyrate also modulates beta-adrenoceptor expression in these cells. Incubation of preadipocytes with 2-10 mM butyrate for 24-48 h promoted a dose- and time-dependent switch in beta-adrenoceptor subtype from a near equal mixture of beta 1 and beta 2 to greater than 85% beta 2 and caused an approximate doubling of the receptor number. beta-Adrenoceptors were assayed in membranes prepared from 3T3-L1 cells using the radiolabeled antagonist [125I]iodocyanopindolol and the beta 2-selective antagonist ICI 118.551. Other short chain acids were not as effective as butyrate in promoting changes in beta-adrenoceptor expression. Cycloheximide (1.0 microgram/ml) inhibited the effects of butyrate on both beta-adrenoceptor subtype and number. Alterations in beta-adrenoceptor phenotype promoted by either butyrate or dexamethasone were functionally correlated with cAMP accumulation in these cells. Comparison of the effects of butyrate and dexamethasone on beta-adrenoceptor expression suggests that these two agents regulate beta-adrenoceptors by different mechanisms.     

番石榴叶天然成分抑制3T3-L1细胞成脂分化的研究

目的观察番石榴叶天然成分槲皮素、槲皮素-3-O-(6″-芥子酸)-β-D-吡喃半乳糖苷(Quercetin-3-O-(6″-eru-coyl)-β-D-galactopyranoside,QEG)及槲皮素-3-O-(6″-阿魏酸)-β-D-吡喃半乳糖苷(Quercetin-3-O-(6″-feruloyl)-β-D-ga-lactopyranoside,QFG)对小鼠3T3-L1细胞成脂分化的影响。方法诱导3T3-L1细胞成脂分化,油红O染色法测定脂滴含量,实时定量PCR(Q-PCR)检测丝氨酸蛋白酶脂肪因子adipsin,CCTTA增强子结合蛋白α(C/EBPα)、过氧化物酶体增殖物激活受体γ(PPARγ)、雌激素受体α(ERα)和雌激素受体β(ERβ)mRNA表达,Western blot检测C/EBPα和PPARγ的蛋白表达。结果 QFG和槲皮素都能抑制3T3-L1细胞成脂分化,而QEG对此没有作用。QFG能够剂量依赖性地抑制成脂分化,并且降低adipsin、C/EBPα和PPARγmRNA及后两者蛋白表达,而对ERα和ERβmRNA的表达没有影响。结论 QFG抑制细胞成脂分化的能力比槲皮素强,其作用主要是通过抑制C/EBPα和PPARγ的表达而实现的,而且可能与雌激素受体途径无关。     

海地瓜硫酸软骨素对3T3-L1前脂肪细胞增殖和分化的影响

目的研究海地瓜硫酸软骨素(Acaudina Molpadioideschondroitin sulfate,AM-CHS)对3T3-L1前脂肪细胞增殖和分化的影响,并探讨其作用机制。方法采用传统的鸡尾酒诱导剂诱导分化3T3-L1前脂肪细胞,以MTT法检测AM-CHS对3T3-L1前脂肪细胞及不同分化阶段3T3-L1细胞增殖活性的影响;分别采用油红O染色和甘油三酯(triglycerides,TG)含量测定法评价其对3T3-L1前脂肪细胞分化的影响。采用RT-PCR法检测脂肪细胞中过氧化物酶体增殖体激活受体γ(peroxisome proliferators-activated receptors gamma,PPARγ)、CCAAT增强子结合蛋白α(CCAAT/enhancer bind-ing protein alpha,C/EBPα)、固醇调节元件结合蛋白-1c(ste-rol regulatory element binding protein-1c,SREBP-1c)等分化相关基因的mRNA表达水平。结果 AM-CHS能明显抑制3T3-L1前脂肪细胞和成熟脂肪细胞的增殖,抑制3T3-L1前脂肪细胞的分化过程,以对分化早期的抑制作用最强。RT-PCR结果表明,AM-CHS能明显降低脂肪细胞PPARγ、C/EBPα和SREBP-1c mRNA的表达。结论海地瓜AM-CHS能明显抑制3T3-L1前脂肪细胞的增殖和分化,其作用机制与下调分化相关基因PPARγ、C/EBPα和SREBP-1c的表达有关。