莱芜猪前体脂肪细胞的原代培养及诱导分化研究

为了建立莱芜猪前体脂肪细胞的体外培养体系,探索猪脂肪组织增生的生物学特征。本研究采集1日龄莱芜猪仔猪颈、背部皮下脂肪组织,采用胶原酶与胰蛋白酶相结合的方法,分离原代前体脂肪细胞,进行前体脂肪细胞的原代和传代培养,以及前体脂肪细胞诱导分化的研究,并采用Real-time PCR方法检测前体脂肪细胞分化过程中关键基因PPARγ的表达。结果表明,分离的猪原代前体脂肪细胞约8h后开始贴壁,贴壁的细胞呈短梭形或不规则的三角形,第3天多数细胞进入指数生长期,呈成纤维细胞样形态,细胞生长曲线近似S形;诱导培养结果显示,少量细胞在第2天开始出现脂滴,大多数细胞在第3天出现脂滴,第7～8天小脂滴逐渐融合成大脂滴,在第12天左右融合成大脂滴,油红O染色呈橘红色。在前体脂肪细胞分化过程中PPARγ基因mRNA的表达量逐渐增加,在诱导后的48h表达量最高,随后其表达丰度逐渐下降。本试验成功建立了莱芜猪前体脂肪细胞培养体系和体外诱导分化模型,为进一步研究莱芜猪前体脂肪细胞增殖与分化机制和猪体脂肪的沉积奠定基础。     

绵羊前体脂肪细胞的分离培养及诱导分化

本试验旨在建立绵羊前体脂肪细胞体外培养方法,为从细胞生物学层面研究绵羊脂肪代谢提供基础。选取1只3月龄杜泊羔羊,颈部处死后取腹股沟脂肪组织,利用Ⅰ型胶原酶消化法分离获得前体脂肪细胞,在完全培养液中培养。当细胞汇合成单层后,用MDI诱导剂(1μmol/L地塞米松,10 mg/L胰岛素,0.5 mmol/L IBMX)诱导2 d,再用胰岛素分化剂(10 mg/L胰岛素)分化2 d之后,细胞分化成脂肪细胞,细胞内出现脂滴,随着时间的延长脂滴汇合,最终脂滴充斥整个细胞。通过细胞形态学动态观察、生长曲线绘制、油红O染色以及诱导分化测定等试验证明,这些细胞是功能活跃的前体脂肪细胞,并在体外重现了其增殖分化的全过程。结果提示,绵羊羔羊腹股沟脂肪组织中存在前体脂肪细胞,且可用以建立绵羊前体脂肪细胞的细胞系,这为从细胞生物学层面研究绵羊脂肪代谢提供了重要基础。     

NR1H3基因调控猪前体脂肪细胞分化的研究

旨在探讨NR1H3基因在猪脂肪组织中的发育性表达规律及对猪前体脂肪细胞成脂分化的影响,以确定其在脂肪沉积过程中的主要功能。本研究采用qRT-PCR方法检测30、90、240日龄马身猪皮下脂肪组织中NR1H3的发育性表达规律;采集5日龄杜长大仔猪背部脂肪组织,分离猪前体脂肪细胞;通过细胞免疫荧光技术检测细胞中Adiponectin含量以鉴定细胞的纯度;构建猪NR1H3基因的过表达载体,设计NR1H3 siRNA序列,分别转染分离得到的猪前体脂肪细胞,采用qRT-PCR、Western blot和油红O染色等方法检测过表达和干扰效率及它们对成脂分化关键基因表达的影响。结果表明,马身猪皮下脂肪组织中NR1H3的表达量随日龄增加呈上升趋势,30日龄时表达量最低,240日龄时表达量最高,差异极显著(P<0.01)。与对照组相比,猪前体脂肪细胞中过表达NR1H3,脂肪细胞的脂滴数明显增多,下游靶标SREBP-1c和ChREBP的表达量极显著提高(P<0.01),且成脂关键基因FAS、C/EBPβ、PPARγ和FABP4的mRNA表达量极显著提高(P<0.01),促进成脂过程;相反,干扰NR1H3基因,脂滴数明显减少,下游靶标及成脂关键基因的mRNA表达量极显著下调(P<0.01),抑制成脂过程。本研究表明,NR1H3基因是猪前体脂肪细胞成脂分化的正调节剂,通过影响其下游靶标SREBP-1c和ChREBP的表达而影响成脂分化,研究结果对阐明猪脂肪沉积的分子机理、改善肉质品质有重要意义。     

绵羊前体脂肪细胞的原代培养及分化

本试验旨在建立绵羊前体脂肪细胞的原代培养方法,探讨反刍动物脂肪沉积机理.以1日龄羔羊的肾周脂肪组织为试验材料,采用组织块法和酶消化法分离培养前体脂肪细胞,观察形态学变化,测定生长曲线,油红O染色检测细胞内脂肪含量,并用实时定量PCR法检测脂蛋白脂酶、过氧化物体增殖剂活化受体γ、脂肪酸合酶的表达量.结果表明:原代培养的细胞成分均一、增殖旺盛、分化率高,具有前体脂肪细胞的形态特征和基因表达特性,为绵羊前体脂肪细胞.本试验成功建立了绵羊前体脂肪细胞原代培养方法,并在体外重现了增殖和分化的过程.     

新西兰兔肌内和皮下前体脂肪细胞原代培养与诱导分化的研究

为建立新西兰兔前体脂肪细胞的体外培养模型,比较新西兰兔肌内和皮下前体脂肪细胞分化过程中相关基因的差异表达,实验采集 1 日龄新西兰兔背最长肌和皮下脂肪组织,采用胶原酶消化方法,分别从 2 种组织中分离前体脂肪细胞,进行细胞原代培养,绘制细胞生长曲线,并对肌内和皮下前体脂肪细胞诱导分化,利用 RT-PCR 检测相关基因的表达变化。结果表明:细胞在分离后 2 h 已经贴壁,24 h 时呈现出短梭形的细胞形态,第 2 天细胞变成长梭形,第 3 天进入对数生长期。肌内和皮下前体脂肪细胞在诱导分化后均被油红O 染色,皮下前体脂肪细胞的脂质积累在诱导分化的第 2 天显著高于肌内前体脂肪细胞(P<0.05);荧光定量结果表明,肌内和皮下前体脂肪细胞 CCAAT 增强子结合蛋白(C/EBPα)基因的表达趋势在诱导分化过程中相同,肌内前体脂肪细胞过氧化物酶体增殖激活受体(PPARγ)第 4 天的表达量显著高于第 6 天,而皮下前体脂肪细胞 PPARγ表达量差异不显著;肌内前体脂肪细胞脂蛋白脂肪酶(LPL)表达量在第 0天和第 2天差异不显著,而皮下前体脂肪细胞第 2 天显著高于第 0 天(P<0.05);肌内前体脂肪细胞脂肪酸合酶(FAS)基因第 0、2、4 天的表达量差异不显著,而皮下前体脂肪细胞第 2、4 天显著高于第 0 天(P<0.05)。本研究成功构建了新西兰兔肌内和皮下前体脂肪细胞的体外培养和诱导分化模型,并发现皮下前体脂肪细胞分化早于肌内前体脂肪细胞,为进一步研究新西兰兔前体脂肪细胞的分化机制和脂肪沉积奠定基础。     

猪前脂肪细胞原代培养方法的建立

目的:摸索猪前脂肪细胞的原代培养方法,为研究猪脂肪发生的分子机制奠定基础.方法:取皮下脂肪,酶消化法分离细胞,用转铁蛋白、氢化可的松、胰岛素诱导分化,油红O染色鉴定.结果:在培养期间,细胞逐渐由梭形变为圆形,并逐渐增大,油红O染色为红色.结论:分离的细胞为未分化的前脂肪细胞,可用此方法培养的细胞进行脂肪发育过程中具体分...     

犊牛前脂肪细胞的培养及其增殖与分化模型的建立

选择犊牛小肠网膜、附睾脂肪垫、腹部皮下脂肪组织材料，应用原代消化细胞培养法培养细胞。结果，由小肠网膜培养出了成分均一、增殖旺盛、分化率高的梭形细胞。经形态学动态变化观察、生长曲线测定、油红O脂肪染色及对胰岛素反应的测定，证明为功能活跃的前脂肪细胞，并在体外重现了其增殖、肥大的全过程。结果显示，小肠网膜脂肪组织存在着功能活跃的可调控的前脂肪细胞。     

猪骨髓间充质干细胞分离培养和诱导分化脂肪细胞

采用全骨髓培养法分离猪骨髓间充质干细胞(Mesenchymal stem cells,MSCs)并传代培养;取第4代纯化的MSCs在成脂诱导培养基中诱导分化;分化的成脂细胞用形态学和油红O染色法进行鉴定;用实时荧光定量PCR(Real-time PCR)检测成脂分化标志基因PPARγ2和LPL mRNA的表达情况。结果显示,分离培养的猪MSCs细胞经连续传代形态上无明显改变;MSCs在成脂分化培养液中诱导分化2d开始有少量脂滴出现,油红O染色成阳性,诱导18d成脂转化率可达59.8%;在诱导分化第5、10、15天时,PPARγ2mRNA相对表达量分别是(5.065±0.159)、(6.268±0.340)、(9.277±0.261),LPL mRNA的相对表达量分别是(10.995±1.473)、(13.130±0.712)、(15.762±0.934)。结果表明,用本诱导条件诱导猪MSCs向脂肪细胞分化,经形态学和油红O染色鉴定,成脂细胞分化率可达60%,且随分化时间的延长,脂肪细胞标志基因表达增加。     

家畜原代前体脂肪细胞离体培养模式研究

本文阐明了家畜原代前体脂肪细胞离体培养模式及其特点、家畜原代前体脂肪细胞有血清培养模式与无血清培养模式、家畜原代前体脂肪细胞离体培养模式中激素、生长因子和细胞因子调控脂肪细胞分化的作用及脂肪细胞离体培养的分化过程以及脂肪细胞分化的鉴定。     

梅山猪耳成纤维细胞体外培养及其克隆

为获得适合于克隆梅山猪的供体细胞,本试验对梅山猪耳皮肤成纤维细胞的分离、培养、纯化、生长特征和核型分析等进行了研究。通过组织块培养法获得梅山猪皮肤成纤维细胞,用胰酶轻度消化后传代3⁴次可得到较纯的皮肤成纤维细胞,并以此作为供体细胞,获得1头健康梅山克隆猪。     

Recruitment and differentiation of intramuscular preadipocytes in stromal-vascular cell cultures derived from neonatal pig semitendinosus muscles

The present study examined the influence of dexamethasone (DEX) treatment on preadipocyte recruitment and expression of CCAAT/enhancing binding protein-alpha (C/EBPalpha) and peroxisome proliferator-activated receptor-gamma (PPARgamma) proteins in stromal-vascular (SV) cell cultures derived from neonatal subcutaneous adipose tissue and semitendinosus muscles. One adipose tissue SV cell culture and one semitendinosus muscle SV cell culture were established from each of six young pigs (5 to 7 d of age). Conventional SV cell-culture procedures were used to digest adipose and muscle tissue and to harvest and culture adipose and muscle SV cells. Muscles were digested after the removal of all visible connective tissue from the excised muscle. One hour after seeding, muscle SV cell cultures were rinsed and refed new media to remove debris and insoluble muscle protein. The SV cell cultures were double-stained for lipid and the AD-3 antibody, a preadipocyte marker, at 1, 3, and 6 d and were double-stained for lipid and C/EBPalpha or PPARgamma at d 6. Preadipocytes were randomly distributed and not clustered after 1 d in muscle and adipose SV cultures. Regardless of treatment, relative and absolute fat cell numbers were lower (P < 0.05) in muscle than in adipose-SV cell cultures. The DEX treatments produced similar magnitudes of increase in relative and absolute preadipocytes and adipocytes in muscle- and adipose-SV cultures. Several extracellular matrix substrata had no influence on adipogenesis in muscle-SV cell cultures. These studies indicate that muscle-SV cultures are characterized by a low number of adipocytes under basal conditions and a low number of glucocorticoid-responsive preadipocytes.     

Glucocorticoids and the differentiation of porcine preadipocytes

The function of glucocorticoids in the differentiation of porcine preadipocytes was examined. Stromal-vascular cell cultures (containing preadipocytes) derived from adipose tissue of the perirenal, ham and shoulder regions of neonatal pigs were incubated in the presence of hydrocortisone at 0 to 100 ng/ml medium. Perirenal cells did not respond to hydrocortisone with an increase in enzyme expression, nor did they demonstrate growth characteristics similar to those of cultures derived from the ham or shoulder. Cultures from the shoulder and ham regions demonstrated dose-responsive increases in enzymatic expression to hydrocortisone. Enzymatic responses by cultures derived from the ham region were lower than responses by cultures from the shoulder region as measured by changes in the activities of sn-glycerol-3-phosphate dehydrogenase and lipoprotein lipase. Addition of insulin to the medium did not produce a synergistic effect with glucocorticoid on differentiation as determined by these enzymatic parameters. However, [14C]glucose metabolism by the cells in culture was synergistically increased by insulin and glucocorticoid supplementation of the medium. The ability of hydrocortisone to induce differentiation of porcine preadipocytes in vitro suggests that the changes that occur in plasma glucocorticoid concentrations during late gestation may play an important role in the rapid development of s.c. adipose tissue in the fetal pig. Secondly, the differences in culture characteristics and hormone responses of cells derived from different locations of adipose tissue formation indicate that differences may exist in the regulation of the growth and development of preadipocytes from different anatomical locations.     

金华猪肌细胞生成素基因的初步研究

运用PCR-RFLP方法对金华猪I系(178头)、II系(30头)、III系(41头)的肌细胞生成素(MyoG)基因的第2内含子内(PCR1-MspⅠ-RFLP)和3'端(PCR2-MspⅠ-RFLP)位点进行多态性分析。结果表明,PCR1-MspⅠ-RFLP位点有3种基因型,即AA型、AB型和BB型,其基因型频率分别为0.1544、0.3826、0.4631;PCR2-MspⅠ-RFLP位点只有2种基因型,MM型和MN型,其基因型频率分别为0.9953和0.0047。     

猪卵母细胞在冷应激条件下的体外发育与CIRP基因表达

本试验旨在研究冷应激对猪卵母细胞发育能力及冷诱导RNA结合蛋白(CIRP)基因表达的影响。常规体外成熟猪GV期卵母细胞,置于室温(25℃)下冷应激处理0.5、1、2、6、12和24 h,观察冷应激处理对其后卵母细胞成熟率和体外受精胚胎发育率的影响和微丝、微管等亚细胞结构的变化,Real-time PCR检测猪卵母细胞CIRP mRNA的表达。结果表明:短时间(2 h)冷应激处理后各组成熟率和体外受精卵裂率均与对照组无异(P0.05);微丝、微管及染色体等亚细胞结构均无明显改变(P0.05),但2 h组的囊胚发育率较对照组有明显下降(9.7%对12.3%,P0.05)。冷应激处理超过2 h后,各组成熟率和囊胚发育率与对照组相比均显著降低(P0.05),微丝、微管正常率均较对照组显著下降(分别为76.8%和53.6%对90.2%和77.2%;P0.05)。在冷应激条件下,猪卵母细胞CIRP mRNA表达水平升高,并在一定范围内随冷应激处理时间的延长而增加,至冷应激处理4 h时达最高。猪卵母细胞在短时间冷应激条件下,其发育能力和亚细胞结构并未受到显著影响;适当的冷应激条件可有效激发猪卵母细胞CIRP mRNA的表达。     

胰岛素对原代培养大鼠前体脂肪细胞增殖分化的影响

对分离自20日龄雄性SD大鼠附睾和肾周白色脂肪组织的前体脂肪细胞进行原代培养，并采用MTT比色法、油红O染色提取法分析了100～400nmol／L胰岛素对其增殖、分化的影响，同时利用半定量RT-PCR分析了该浓度胰岛素对分化标志基因——脂肪酸合酶（FAS）、乙酰CoA羧化酶α（ACC1）基因mRNA表达的影响。结果显示，胰岛素能有效地促进前体脂肪细胞的增殖和分化（P〈0．05），在400nmol／L以下具有剂量依赖性；胰岛素处理72h能显著提高脂肪细胞FAS和ACC1基因mRNA的表达水平（P〈0．05）。证实胰岛素对原代培养大鼠前体脂肪细胞增殖分化有明显促进作用。     

Insulin-like growth factor 1 induction of differentiation of porcine preadipocytes

The role of insulin-like growth factor I (IGF-1) in the development of the porcine preadipocyte was studied. Primary cultures of stromal-vascular cells (containing preadipocytes) were derived from s.c. adipose tissue of pigs at 1 d of age by enzyme digestion and centrifugation. Cells were cultured for a total of 15 d. Cells were exposed to IGF-1 at concentrations of 0, 5, 25 or 50 ng/ml medium during one of four time periods: d 1-15, d 1-5, d 13-15, or 4 h on d 15 of culture. IGF-1 had a mitogenic effect on cells during the first three time periods as determined by coulter counting. IGF-1 induced the enzymatic differentiation of porcine preadipocytes following exposure for either the entire 15 d of culture or for only 48 h (d 13-15) after confluency had been attained (d 5). Histochemically, lipid accumulation over time paralleled changes in enzyme activity. Incubation of IGF-1 with the cell cultures during the logarithmic phase of growth (d 1-5) or for 4 h on d 15 did not affect enzyme activity. These data indicate that IGF-1 can induce the differentiation of porcine preadipocytes after the cells leave the logarithmic phase of growth through action on post-confluent events.     

t10,c12-CLA对猪皮下和背最长肌脂肪前体细胞增殖与分化的影响

试验首先建立了30日龄猪皮下脂肪和背最长肌组织块培养及皮下和肌内前脂肪细胞体外培养体系,共设2个处理,处理1为阴性对照(添加0.1mmol/lBSA),处理2添加100μmol/l的t10,c12-CLA,每个处理设6个平行,接种时即加入BSA与t10,c12-CLA进行处理至第10d。试验全期通过MTT法(采用上述前脂肪细胞培养体系)及油红O染色技术(采用上述组织块培养体系)从细胞形态学角度探讨t10,c12-CLA对皮下和肌内脂肪前体细胞增殖与分化的影响,同时采用荧光定量PCR技术测定t10,c12-CLA对猪皮下和肌内脂肪前体细胞关键分化转录因子(PPARγ,ADD1,SEEBP1)的影响。MTT法和油红O染色结果表明:100μmol/lt10,c12-CLA显著抑制了猪皮下脂肪前体细胞增殖与分化,显著促进了猪肌内脂肪前体细胞的分化(P0.05),但对其增殖影响不显著,本部分结果从细胞形态学角度说明t10,c12-CLA对猪皮下和肌内脂肪前体细胞增殖与分化存在差异调控作用、荧光定量PCR结果表明:100μmol/lt10,c12-CLA显著抑制了猪皮下脂肪PPARγ的基因表达,促进了猪背最长肌PPARγ和ADD1的基因表达(P0.05),本部分结果从前脂肪细胞分化调控角度说明t10,c12-CLA对猪皮下和肌内脂肪前体细胞增殖与分化的差异调控机制。