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DNA甲基化与去甲基化调控脂肪沉积的研究进展 总被引：2，自引：2，他引：0
脂肪沉积是一个复杂的生物学过程,受遗传和表观遗传的调控作用。DNA甲基化和去甲基化是表观遗传修饰的重要方式,可通过与转录因子的相互作用或改变染色质的结构调控基因的表达,进而参与机体生长发育和细胞分化等重要的生命过程。动物脂肪沉积是脂肪细胞增殖分化和肥大的结果,脂肪细胞分化是由多能干细胞经前体脂肪细胞向成熟脂肪细胞转化的过程。相关研究表明,转录因子过氧化物酶体增殖物激活受体γ(peroxi-some proliferator activiated receptorγ,PPARγ)和CCAAT增强子结合蛋白家族(CCAAT enchancer binding proteinfamily,CEBPs)在脂肪沉积过程中起关键调控作用。近期研究发现,DNA甲基化可以通过调控脂肪形成过程中相关基因的表达而参与脂肪细胞的分化和脂肪组织的生长发育。去甲基化也可影响动物脂肪沉积过程,但其具体机制目前尚不清楚。作者主要介绍了DNA甲基化和去甲基化的定义、发生位点、生物学功能、参与DNA甲基化和去甲基化过程中的酶及其作用机制,概述了脂肪沉积过程及PPARγ、C/EBPα等转录因子在脂肪沉积过程中的调控作用,重点阐述了DNA甲基化和去甲基化对脂肪形成相关基因的表达和对脂肪细胞分化的影响,旨在为阐明脂肪沉积机制及改善动物肉质品质提供参考。 相似文献
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The purpose of this study was to detect differential expression of genes related to adipocyte differentiation in pigs by suppression subtractive hybridization. Adipocytes and stromal vascular cells (a fraction containing preadipocytes) from pig adipose tissue were isolated for mRNA extraction. The cDNA from preadipocytes was subtracted from the cDNA from adipocytes. The subtracted gene fragments were cloned into pGEM-T Easy TA cloning vector. We selected 384 clones for gene sequence determination and for further analysis. These genes were subjected to a differential screening procedure to confirm the differential expression of genes between the 2 cell types. We found that at least 36 genes were highly expressed in the adipocytes compared with preadipocytes. Among these, 6 genes including 2 novel genes with the greatest differences were selected and confirmed by Northern analysis. We found that angiotensin I-converting enzyme (ACE), ataxia-telangiectasia mutated protein (ATM), calpain 1, and stearoyl coenzyme A desaturase 1 (SCD1) were highly expressed in adipocytes compared with preadipocytes (P < 0.05). The relative mRNA abundance of ACE, ATM, calpain 1, SCD1, and 2 novel genes discovered in the current study was increased at the later stages of adipocyte differentiation (P < 0.05). The results confirmed that the genes involved in lipid metabolism and adipocyte differentiation were highly expressed in porcine adipocytes. However, further investigation is needed to demonstrate specific functions of the novel genes discovered in the current study. 相似文献
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Role of fatty acids in adipocyte growth and development 总被引：5，自引：0，他引：5
Azain MJ 《Journal of animal science》2004,82(3):916-924
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利用半定量RT-PCR法分析比较了甘油三酯水解酶(Triacylglycerol hydrolase,TGH)和激素敏感脂酶(Hormone-sensitive lipase,HSL)基因在不同猪种、不同发育阶段及不同部位脂肪组织中转录表达的差异,探讨其在猪脂肪组织的表达规律。结果显示,脂肪型个体TGHmRNA表达丰度显著低于瘦肉型和杂交型个体,成年猪较初生仔猪低,皮下、腹膜和内脏脂肪组织中TGH表达量依次递增;其变化规律与HSL相同。此外,对分离培养的原代前体脂肪细胞通过诱导分化和油红O染色区分分化状态,分析TGHmRNA表达的时序变化,发现TGH在前脂肪细胞中不转录表达,诱导分化后开始表达,且在诱导分化第4天表达量最高,分化第10天表达量下降,达到峰值的时间较HSL早。结果表明,TGH的表达与个体肥胖程度、年龄、脂肪组织部位以及脂肪细胞分化程度相关,同时,在脂肪细胞分化过程中,TGH表达峰值早于HSL,提示TGH在脂肪细胞发育过程中可能较早承担基础脂解作用。 相似文献
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【目的】 扩增猪血清和糖皮质激素诱导型激酶（SGK）家族基因并进行生物信息学分析,探索其在猪脂肪组织和细胞中的表达模式。【方法】 以藏猪脂肪细胞cDNA为模板PCR扩增SGK家族基因,通过在线工具预测其编码蛋白的理化性质及亚细胞定位;用Mega X软件构建系统进化树;采集30日龄巴马猪心脏、肝脏、脾脏、肾脏、肺脏、背肌、腿肌、颈部脂肪、背部脂肪、腹股沟脂肪、肾周脂肪等组织及7日龄和4月龄猪腹股沟脂肪组织,通过实时荧光定量PCR检测SGK家族基因在猪不同部位组织中的表达;采集30日龄巴马猪腹股沟脂肪组织并分离基质血管成分（SVF）细胞,诱导SVF细胞向白色脂肪细胞分化,通过实时荧光定量PCR检测SGK家族基因及脂肪分化标记基因CCAAT增强子结合蛋白α（C/EBPα）、过氧化物酶体增殖物激活受体（PPARγ）在脂肪细胞中的表达。【结果】 SGK1、SGK2和SGK3基因CDS区序列长度分别为1 296、1 104和1 473 bp,分别编码431、367和490个氨基酸;SGK1和SGK2定位于细胞质,SGK3定位于细胞核,三者均为亲水性蛋白,3个蛋白均含有相同基序,保守性高;系统进化树结果表明,猪与牛的亲缘关系最近;SGK1和SGK3基因在心脏、肝脏、脾脏、肺脏、肾脏、多种肌肉及脂肪组织广泛表达,SGK2基因在颈部、背部、腹股沟、肾周脂肪组织中均有较高表达;SGK1和SGK2基因在7日龄猪脂肪组织中表达量极显著高于4月龄猪脂肪组织（P<0.01）,SGK3基因在4月龄和7日龄的猪脂肪组织中表达量无显著差异（P>0.05）,且SGK3基因的表达量低于SGK1和SGK2基因;与未分化脂肪细胞相比,在分化后的脂肪细胞中SGK1和SGK2基因的表达量极显著上调（P<0.01）,且SGK1基因的表达量远高于SGK2基因,而SGK3基因的表达量无显著变化（P>0.05）。【结论】 SGK家族蛋白具有保守结构域,可能发挥着相似的功能,SGK1和SGK2可能参与调控猪脂肪细胞的分化过程,结果可为探究猪脂肪沉积的分子机制提供一定的理论基础。 相似文献
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Adipose tissue angiogenesis 总被引：10，自引：0，他引：10
A review of adipose tissue angiogenesis includes the morphological and cytochemical development of adipose tissue vasculature and the concept of primitive fat organs. Spatial and temporal relationships between fetal vascular and fat cell development are discussed, including depot- and genetic-dependent arteriolar differentiation. The relationship between connective tissue deposition and elaboration of adipose tissue vasculature is discussed with respect to regulating adipocyte development in a depot-dependent manner. In vitro studies indicated that depot-dependent vascular traits may be attributable to intrinsic growth characteristics of adipose tissue endothelial cells. These studies indicate that adipogenesis may be regulated by factors that drive angiogenesis. Fundamental aspects of angiogenesis, including basement membrane breakdown, vasculogenesis, angiogenic remodeling, vessel stabilization, and vascular permeability were reviewed. Critical angiogenic factors include vascular endothelial growth factor (VEGF), VEGF receptors, angiopoietins (Ang), ephrins, matrix metalloproteinases, and the plasminogen enzymatic system. Vascular endothelial growth factor is the most critical factor because it initiates the formation of immature vessels and disruption of a single VEGF allele leads to embryonic lethality in mice. Expression of VEGF is influenced by hypoxia, insulin, growth factors, and several cytokines. Angiogenic factors secreted and/or produced by adipocytes or preadipocytes are discussed. Vascular endothelial growth factor expression and secretion by adipocytes is regulated by insulin and hypoxia, and is associated with adipose tissue accretion. Vascular endothelial growth factor accounts for most of the angiogenic activity of adipose tissue. The proposed role of leptin as an adipogenic factor is reviewed with respect to efficacy on various aspects of angiogenesis relative to other angiogenic factors. The VEGF and leptin genes are both hypoxia inducible, but potential links between VEGF and leptin gene expression have not been examined. Finally, several studies including a study of mice treated with antiangiogenic factors indicate that adipose tissue accretion can be controlled through the vasculature per se. 相似文献
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本试验旨在研究环腺苷酸（3',5'-cyclic adenosine monophosphote,cAMP）环化酶合成酶2（adenylyl cyclase 2,ADCY2）基因对延边黄牛脂肪前体细胞成脂分化的影响。选取3日龄的延边黄牛腹股沟皮下脂肪组织进行脂肪前体细胞的分离、培养和诱导分化;设计ADCY2基因的干扰片段（siADCY2-1、2、3）,构建pEX4过表达载体;分别收集正常诱导（对照组）、干扰和过表达0、5和10 d的脂肪细胞。用实时荧光定量PCR检测过氧化物酶体增殖激活物受体（PPARγ）、CCAAT/增强子结合蛋白（C/EBPα）和ADCY2在细胞分化过程中mRNA的转录水平,并用Western blotting法检测其蛋白的表达;用油红O染色检测脂滴含量的变化;用甘油三酯试剂盒检测甘油三酯含量。试验结果表明,在成脂分化过程中,与未分化相比,ADCY2基因在分化的第5和10天表达量均极显著上升（P<0.01）,而分化第10天与第5天相比水平极显著下降（P<0.01）;siADCY2-1干扰效率最高,过表达ADCY2基因使其mRNA水平升高;与对照组相比,过表达组细胞内ADCY2基因mRNA水平提高了约4 000 000倍,脂肪细胞内脂滴含量和甘油三酯的含量极显著提高（P<0.01）,成脂关键基因C/EBPα和PPARγ表达极显著上调（P<0.01）,而RNA干扰组细胞内ADCY2基因mRNA水平极显著降低（P<0.01）,脂肪细胞内脂滴含量和甘油三酯的含量极显著下降,成脂关键基因C/EBPα和PPARγ表达极显著下调（P<0.01）。因此,ADCY2基因过表达能显著增加成熟脂肪细胞的脂滴含量及甘油三酯含量,促进成脂关键基因C/EBPα和PPARγ的表达,说明ADCY2基因对脂肪细胞分化具有正向调控作用。 相似文献
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旨在鉴定非编码RNA circNMT1,明确其组织和细胞的表达模式,以及探究过表达circNMT1对脂肪细胞分化的影响。本试验以30月龄中国沼泽水牛(信阳水牛,n=3)的心、肝、脾、肺、肾、背最长肌、背部皮下脂肪组织和前体脂肪细胞以及3T3-L1细胞为试验材料。通过半定量PCR和实时荧光定量PCR (real-time quantitative PCR,qRT-PCR)技术对circNMT1进行鉴定、细胞定位并明确其时空表达模式。进一步分别将其过表达到3T3-L1和水牛前体脂肪细胞中,利用形态学方法及定量方法检测过表达后脂滴累积情况,同时采用qRT-PCR检测脂肪标志基因相对表达水平的变化。结果表明,circNMT1是真实存在且稳定表达的circRNA,在水牛前体脂肪细胞的细胞核和细胞质中均表达,且在脂肪组织和成熟的脂肪细胞中高表达(P<0.001)。功能获得性试验表明,在3T3-L1细胞和水牛脂肪细胞,circNMT1显著促进脂肪细胞的脂滴积累,并且显著提高成脂标志基因PPARG、C/EBPα和FABP4的相对表达水平(P<0.01)。circNMT1可能是水牛脂肪细胞分化的正调控因子,这为circNMT1在水牛脂肪细胞中的调节作用提供了新见解。 相似文献
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旨在克隆山羊NR4A1基因的CDS区序列,明确其组织和细胞表达模式,以及探究过表达NR4A1基因对山羊皮下脂肪细胞分化的影响。本试验利用双酶切法构建山羊过表达载体pcDNA3.1-NR4A1。以1周岁简州大耳羊（n=5）为试验动物。利用RT-PCR方法和实时荧光定量PCR（real-time quantitative PCR, qPCR）技术克隆NR4A1基因编码区序列并明确其时空表达特性,再将山羊pcDNA3.1-NR4A1载体转染皮下脂肪细胞使NR4A1过表达,利用形态学方法检测过表达后脂滴聚集的变化,同时采用qPCR方法检测脂肪分化标志基因相对表达水平的变化。结果获得山羊NR4A1基因的编码区序列是1 797 bp,编码598个氨基酸;NR4A1在山羊各组织中广泛表达,且在山羊背最长肌中的相对表达水平最高（P<0.01）,在山羊皮下脂肪细胞分化60 h表达量最高（P<0.01）;过表达NR4A1基因显著促进山羊皮下脂肪细胞的脂滴积累,并且显著提高C/EBPα、C/EBPβ、PPARγ、LPL、SREBP1和AP2的相对表达水平（P<0.05）。NR4A1基因可能是山羊皮下脂肪细胞分化的正调控因子,且可能是协同脂肪分化标志基因的表达量来实现的。 相似文献
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为了探究小尾寒羊脂肪细胞分化过程中相关基因的变化规律,试验采集2月龄小尾寒羊腹股沟白色脂肪组织,通过酶消化法体外分离小尾寒羊前体脂肪细胞。培养前体脂肪细胞布满细胞板后,分别用诱导Ⅰ液、诱导Ⅱ液对细胞进行诱导分化,使其成为成熟的脂肪细胞。利用油红O染色法验证成熟脂肪细胞并检测脂滴含量。分别在增殖期细胞增殖70%、90%及分化期诱导Ⅰ液处理48 h、诱导Ⅱ液处理48 h、完全培养液处理48 h时（2、4、6、8、10 d）提取细胞总RNA,反转录成cDNA。采用实时荧光定量PCR检测PPARγ、C/EBPα、LPL、SREBP1、KLF5、KLF6、FABP4、STAT5、ACSS2、IGF1、ADD1、FOXO1、ACACA、DGAT1、CPT1A基因的表达规律。结果表明,试验成功分离并诱导前体脂肪细胞变为成熟的脂肪细胞,细胞内部具有明显脂滴;实时荧光定量PCR结果表明,上述基因在细胞分化阶段具有明显波动,峰值出现的时间均不相同;C/EBPα、FOXO1基因表达峰值出现在第6天,可能在细胞分化早期发挥作用;PPARγ、LPL、SREBP1、KLF5、KLF6、FABP4、STAT5、ADD1、ACSS2基因表达峰值出现在第8天,但表达倍数与趋势均不相同;ACACA基因表达量出现上下波动;IGF1、DGAT1基因表达峰值出现在第10天;CPT1A基因表达量则一直下降;FABP4基因表达倍数显著高于其他基因。本研究全面检测了小尾寒羊前体脂肪细胞在分化过程中关键基因的表达规律,可为探究小尾寒羊脂肪分化过程分子机制、挖掘参与脂肪分化新的关键基因、提高小尾寒羊肌间脂肪含量等研究提供一定的理论参考。 相似文献
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Pickworth CL Loerch SC Velleman SG Pate JL Poole DH Fluharty FL 《Journal of animal science》2011,89(2):355-366
Genetic regulation of the site of fat deposition is not well defined. The objective of this study was to investigate adipogenic differentiation state-specific gene expression in feedlot cattle (>75% Angus; <25% Simmental parentage) of varying adipose accretion patterns. Four groups of 4 steers were selected via ultrasound for the following adipose tissue characteristics: low subcutaneous-low intramuscular (LSQ-LIM), low subcutaneous-high intramuscular (LSQ-HIM), high subcutaneous-low intramuscular (HSQ-LIM), and high subcutaneous-high intramuscular (HSQ-HIM). Adipose tissue from the subcutaneous (SQ) and intramuscular (IM) depots was collected at slaughter. The relative expression of adipogenic genes was evaluated using quantitative PCR. Data were analyzed using the mixed model of SAS, and gene expression data were analyzed using covariate analysis with ribosomal protein L19 as the covariate. No interactions (P > 0.10) were observed between IM and SQ adipose tissue depots for any of the variables measured. Therefore, only the main effects of high and low accretion within a depot and the effects of depot are reported. Steers with LIM had smaller mean diameter IM adipocytes (P < 0.001) than HIM steers. Steers with HSQ had larger mean diameter SQ adipocytes (P < 0.001) than LSQ. However, there were no differences (P > 0.10) in any of the genes measured due to high or low adipose accretion. Preadipogenic delta-like kinase1 mRNA was greater in the IM than the SQ adipose tissue; conversely, differentiating and adipogenic genes, lipoprotein lipase, PPARγ, fatty acid synthetase, and fatty acid binding protein 4 were greater (P < 0.001) in the SQ than the IM depot. Intramuscular adipocytes were smaller than SQ adipocytes and had greater expression of the preadipogenic gene, indicating that more hyperplasia was occurring. Meanwhile, SQ adipose tissue contained much larger (P < 0.001) adipocytes that had a greater expression (P < 0.001) of differentiating and adipogenic genes than did the IM adipose tissue, indicating more cells were undergoing differentiation and hypertrophy. Adipogenic differentiation state-specific gene expression was not different in cattle with various phenotypes, but adipogenesis in the SQ and IM adipose tissues seems to occur independently. 相似文献
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Characterization of key genes of the renin–angiotensin system in mature feline adipocytes and during in vitro adipogenesis 
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下载免费PDF全文 J. Riedel B. Badewien‐Rentzsch B. Kohn L. Hoeke R. Einspanier 《Journal of animal physiology and animal nutrition》2016,100(6):1139-1148
Obesity is a growing health problem in humans as well as companion animals. In the development and progression of obesity‐associated diseases, the members of the renin–angiotensin system (RAS) are proposed to be involved. Particularly, the prevalence of type 2 diabetes mellitus in cats has increased enormously which is often been linked to obesity as well as to RAS. So far, reports about the expression of a local RAS in cat adipocytes are missing. Therefore, we investigated the mRNA expression of various RAS genes as well as the adipocyte marker genes adiponectin, leptin and PPAR‐γ in feline adipocytes using quantitative PCR. To characterize the gene expression during adipogenesis, feline pre‐adipocytes were differentiated into adipocytes in a primary cell culture and the expression of RAS key genes measured. All major RAS components were expressed in feline cells, but obvious differences in the expression between pre‐adipocytes and the various differentiation stages were found. Interestingly, the two enzymes ACE and ACE2 showed an opposite expression course. In addition to the in vitro experiments, mature adipocytes were isolated from subcutaneous and visceral adipose tissue. Significant differences between both fat depots were found for ACE as well as AT1 receptor with greater expression in subcutaneous than in visceral adipocytes. Visceral adipocytes had significantly higher adiponectin and PPAR‐γ mRNA level compared to the subcutaneous fat cells. Concerning the nutritional status, a significant lower expression of ACE2 was measured in subcutaneous adipocytes of overweight cats. In summary, the results show the existence of a potentially functional local RAS in feline adipose tissue which is differentially regulated during adipogenesis and dependent on the fat tissue depot and nutritional status. These findings are relevant for understanding the development of obesity‐associated diseases in cats such as diabetes mellitus. 相似文献
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Adipose triglyceride lipase (ATGL), a newly identified lipase, is a rate-limiting enzyme for triglyceride hydrolysis in adipocytes. The regulatory proteins involved in ATGL-mediated lipolysis in fat tissue are not fully identified and understood. The G(0)/G(1) switch gene 2 (G0S2) is an inhibitor of ATGL activity by interacting with ATGL through the hydrophobic domain of G0S2. Here, for the first time, we have cloned the coding sequence of G0S2 cDNA for the chicken, turkey, and quail. Sequence comparisons with mammals revealed that the avian G0S2 also have a conserved hydrophobic domain. Avian G0S2 is predominantly expressed in adipose tissues relative to other tested tissues. Within the adipose tissue, G0S2 is expressed 20-fold greater in the adipocyte than in the stromal-vascular (SV) fraction (P < 0.001). Expression of G0S2 mRNA gradually increased during differentiation of chicken adipocytes in culture (P < 0.05). However, there is G0S2 expression in embryonic adipose tissue, SV fraction, and primary preadipocytes before confluence that generally have an increased capacity of cell proliferation, which indicates it has an important role in adipocyte differentiation rather than proliferation. For a better understanding of how G0S2 responds to environmental stimuli, chickens were fasted for 24 h and then refed. Expression of G0S2 in adipose tissue was dramatically decreased (P < 0.05) in the chickens and quail after a 24-h fasting period, and increased to the control level after refeeding. In contrast to G0S2 expression, ATGL expression was induced (P < 0.05) after the 24-h fasting period and rapidly returned to the control level during the refeeding period. These data indicate that changes in lipolytic activities of adipose tissue in vivo can be regulated by G0S2 expression, as an inhibitor of ATGL. 相似文献