IGF-Ⅰ、GH和CLA对脂肪前体细胞增殖、分化和基因表达的影响

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。     

表皮生长因子（EGF）对牛前脂肪细胞增殖和分化的影响

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.     

抵抗素对猪前脂肪细胞增殖与分化的影响

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.     

油酰甘氨酸对C2C12成肌细胞增殖、分化和蛋白质沉积的影响

脂酰氨基酸是一类脂肪酸和氨基酸缩合生成的内源性化合物,在镇痛抗炎、细胞增殖和细胞凋亡等方面具有重要的调控作用.为探讨脂酰氨基酸对骨骼肌发育的影响,本研究以小鼠(Mus musculus)成肌细胞(myoblast cell line,C2C12)为对象,分别采用细胞计数检测法和肌酸激酶活性分析油酰甘氨酸(N-Oleoyl glycine,OLGly)对C2C12细胞的增殖和分化水平的影响.同时用qRT-PCR检测了增殖细胞核抗原、细胞周期素依赖性激酶抑制因子和生肌调节因子5、成肌素的mRNA表达水平.并且,本实验一方面测定了细胞总蛋白含量,另一方面采用Westem blot法检测嘌呤霉素掺入水平,分析了蛋白质沉积相关蛋白以及蛋白质降解相关蛋白的表达水平.结果发现,与无水乙醇对照组相比,基础培养液中分别添加0.2、2和20 μmol/L OLGly对C2C12细胞的数目、肌酸激酶活性以及增殖和分化标志基因表达水平均无显著影响;而蛋白质合成研究结果表明,OLGly可以剂量依赖性提高细胞总蛋白含量(P＜0.05),此外,研究还发现,在OLGly处理组中,细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)蛋白和核糖体蛋白亚型6(ribosomal protein subunit6,rpS6)蛋白的表达水平均呈现剂量和时间依赖性升高(P＜0.05).进一步研究发现,OLGly对蛋白质降解通路相关蛋白的表达无显著性影响.综合上述研究结果可见,OLGly能促进C2C12细胞蛋白质合成,但对其增殖和分化无明显影响.究其机制,可能与ERK和rpS6的蛋白表达水平的上调有关.研究结果为研制调控肌肉发育和蛋白质沉积的新型功能性调控物提供了实验依据.     

乙烯通过调控氧化还原水平和耐冷基因表达提高早稻秧苗耐低温胁迫能力

乙烯参与调控植物响应多种逆境胁迫，然而乙烯调控早稻秧苗响应低温胁迫的生理和分子机制还不明确。本研究选择无土基质、发酵基质和营养土3种育秧基质对中早39早稻品种进行正常育秧至两叶一心期，外源喷施乙烯利后将水稻秧苗进行3d的低温处理，随后测定秧苗理化性质和抗寒基因表达，同时以喷施等量清水作为对照。结果显示：喷施乙烯利后显著提高了低温条件下水稻秧苗的生长，提高了秧苗体内的养分含量和渗透调节物质脯氨酸和可溶性糖含量，增强了秧苗体内抗氧化系统酶活性和氧化还原状态(AsA/DHA比率)，提高了秧苗体内OsCOIN、TERF2、OsLti6a和OsCDPK7等耐冷基因的表达。以上结果说明，外源喷施乙烯通过调控水稻体内渗透调节物质含量、氧化还原水平和耐冷基因的表达增强水稻秧苗的耐低温胁迫能力。     

红壤农业生态系统养分循环、平衡和调控研究

本文运用５年的定位资料,较系统的论述了红壤农业生态系统养分循环和平衡规律,讨论并举例说明了如何评价养分平衡的问题,同时,提出了调控养分循环和平衡的一些具体措施。     

植物小肽研究进展I：来源、鉴定和调控

小肽通常指5~60个氨基酸长度的肽段。自1991年在番茄中首次报道植物小肽-系统素参与番茄病虫害引起的伤害反应以来,已发现和报道了众多的植物小肽,它们参与植物生长发育的调控、植物和微生物的互作以及对生物和非生物胁迫等逆境的响应。本文就近30 a来在植物小肽的来源、鉴定和调控方面的研究进展作初步总结,并讨论存在的问题和未来的研究方向。     

植物小肽研究进展Ⅰ：来源、鉴定和调控

小肽通常指5～60个氨基酸长度的肽段。自1991年在番茄中首次报道植物小肽-系统素参与番茄病虫害引起的伤害反应以来,已发现和报道了众多的植物小肽,它们参与植物生长发育的调控、植物和微生物的互作以及对生物和非生物胁迫等逆境的响应。本文就近30 a来在植物小肽的来源、鉴定和调控方面的研究进展作初步总结,并讨论存在的问题和未来的研究方向。     

苏云金杆菌的杀虫蛋白质和基因的结构,特点,分化及调控的研究…

苏云金杆菌（Ｂｔ）是一种非常重要的昆虫病原细菌，其产生的杀虫白南对许多农业和医学上的重要害虫包括鳞翅目、鞘翅目、双翅目、膜翅目，螨类和线虫等都有高特异的杀虫活性，其菌剂早已商品化，并已在世界各地广泛应用。近年来，对Ｂｔ遗传学、分子生物学和遗传工程等方面的研究已获得了重大的进展。本文将系统评述Ｂｔ杀虫蛋白质基因的特点，分类体系、基因的表达和调控以及杀虫蛋白质的三维结构等方面世界上的最新研究进展。此外     

隔沟交替灌溉对棉花耗水、产量和品质的调控效应

在甘肃省石羊河流域下游民勤县干旱荒漠绿洲区研究了覆膜条件下隔沟交替灌溉(AFI)和常规沟灌(CFI)对棉花耗水、产量和品质的调控效应.结果表明,现蕾期和花期,AFI处理的棉花日耗水强度小于CFI处理;铃期和吐絮期,AFI处理棉花日耗水强度大于相同灌水定额的CFI处理.相同灌水定额条件下,AFI处理有利于籽棉产量和霜前花产量的提高,灌水定额为375 m3·hm-2和480 m3·hm-2的AFI处理,籽棉产量和WUE显著高于相同灌水定额的CFI处理.相同灌水定额条件下,AFI和CFI处理的衣分无显著性差异.2005年AFI处理的平均纤维长度比CFI处理长2.6mm,灌水定额为225m3·hm-2处理两者差异显著;2006年不同灌水方式下的纤维长度无显著差异,可能与降雨情况有关.在干旱缺水地区覆膜隔沟交替灌溉是一种有效的节水灌溉模式.在棉花品质不降低的情况下,有利于产量和水分利用效率的提高.     

Leptin对猪成肌细胞中PGC-1α、UCPs mRNA表达的影响

摘要：本实验采用链酶蛋白酶消化法获得猪成肌细胞， MyoG和MyoD的RT-PCR和Desmin免疫组化染色鉴定猪成肌卫星细胞后，分别研究外源leptin对猪成肌细胞产热相关基因PGC-1α和 UCPs mRNA表达的影响。对产热相关基因的RT-PCR检测结果表明，30 nmol/L 和100nmol/LLeptin均可促进成肌细胞中PGC－1αmRNA表达，100nmol/L Leptin作用效果显著高于30 nmol/L，且作用24h促进效果明显优于12h作用效果(p<0.05)。30nmol/LLeptin可明显提高成肌细胞中UCP2mRNA的表达，且作用24h促进效果明显优于12h处理效果(p<0.05)， 100nmol/L leptin作用效果显著低于30nmol/L Leptin作用效果，但显著高于对照组(p<0.05)。30 nmol/L 和100nmol/L leptin均不影响 UCP3mRNA的表达(p<0.05)。以上研究结果提示，Leptin可能通过上调PGC-1α和UCP2转录，促进成肌细胞能量消耗。     

Inhibitory effect of phenolic acids on the proliferation of 3T3-L1 preadipocytes in relation to their antioxidant activity

Obesity is an important topic in the world of public health and preventive medicine. Inhibition of preadipocyte proliferation plays an important role in the mechanisms of proposed antiobesity. In this in vitro study, the inhibitory effect of phenolic acids on 3T3-L1 preadipocytes was evaluated, and a relationship analysis was then conducted. The results showed that the addition of phenolic acids to the growth medium decreased the cell population growth of 3T3-L1 preadipocytes. The IC50 values of chlorogenic acid, gallic acid, o-coumaric acid and m-coumaric acid on 3T3-L1 preadipocytes were 72.3, 43.3, 48.2, and 49.2 microM, respectively. A relationship analysis indicated that there is a significant linear correlation between the influence of phenolic acids on cell population growth and their antioxidant activity (r = 0.77, p < 0.01). The cell cycle assay indicated that the treatment of 3T3-L1 preadipocytes with chlorogenic acid, o-coumaric acid, and m-coumaric acid caused cell cycle arrest in the G1 phase. Gallic acid did not affect the cell cycle profile; however, it increased the number of apoptotic cells (sub-G1 phase) in a time- and dose-dependent manner. Annexin V-fluorescein isothiocyanate (FITC)-propidium iodide (PI) apoptosis flow cytometric assay showed that gallic acid increased the number of early apoptotic (annexin V-FITC+/PI-) and late apoptotic cells (annexin V-FITC+/PI+) but not necrotic cells (annexin V-FITC-/PI+). The treatment of cells with gallic acid caused the loss of mitochondrial membrane potential (delta psi(m)). These results indicate that the inhibition of preadipocyte population growth by some phenolic acids might have further implication in in vivo antiobesity effects.     

Effects of conjugated linoleic acid (CLA) isomers on oxygen diffusion-concentration products in liposomes and phospholipid solutions

Conjugated linoleic acids (CLAs) are a group of octadecadienoic acids (18:2) that are naturally present in food products and may have beneficial health effects. Liposomes and ethanol solutions were prepared by mixing synthetic phosphatidylcholines (PCs) with c9,t11-CLA, t10,c12-CLA, and linoleic acid (LA) in the sn-2 position into natural PCs from soybean, egg yolk, rat brain, and rat heart at 5 mol %. The oxygen diffusion-concentration products were measured using electron spin resonance spin-label oximetry methods. Individual synthetic PCs, the phospholipid matrix, and the tested lipid systems all exhibited influence on oxygen diffusion-concentration products during lipid peroxidation. Incorporating 5 mol % PC(c9,t11-CLA) into soy and egg yolk PC increased oxygen consumption in liposome suspensions while it was decreased in rat heart and brain PCs. On the other hand, PC(t10,c12-CLA) increased oxygen consumption in mixtures with egg yolk and rat heart PC but decreased it in soybean and rat brain PC. By comparison, PC(LA) decreased oxygen consumption in every case. In ethanol solutions, all of the synthetic PCs suppressed the capacity to generate peroxide radicals in the order of LA > c9,t11-CLA > t10,c12-CLA. In addition, PCs containing individual CLA isomers and LA differed in their capacities to react with and quench DPPH radicals in both ethanol solution and liposome, suggesting differences between CLA isomers and LA in DPPH radical-fatty acid interactions. Incorporation of CLA isomers and LA into dimyristyl-PC reduced the phase transition temperature from 23.6 to 23.1 and 23.3 degrees C, respectively. The results of this study provide evidence that the behavior of CLA isomers differs in the microenvironment of membranes possibly due to structural differences that affect the permeability of membranes to oxygen and lipid peroxidation.     

猪前体脂肪细胞与肌卫星细胞体外联合培养的初步研究

目的：初步建立猪前体脂肪细胞与肌卫星细胞体外联合培养的方法，探讨联合培养模式下两类细胞的基本生长特性。方法：利用差速贴壁法分别纯化前体脂肪细胞与肌卫星细胞，按1：10的浓度比接种混合培养，以单独两类细胞培养作对照；采用油红O染色、Desmin免疫组化染色鉴定；通过形态学观察、MTT比色绘制生长曲线研究细胞生长规律。结果：Desmin免疫组化染色观察肌细胞阳性率达97%以上，油红O染色计数诱导分化细胞比率大于60%；形态学观察发现，联合培养细胞接触汇合前形态呈梭形，接触后不规则重叠交织生长；充脂细胞呈现较晚，且数量稀少； HE染色可见多核细胞融合及肌管样结构；测定2～9d细胞生长曲线显示，联合细胞组增殖比率大于对照组，经历2～3d潜伏期、3～7d指数生长期后，并未与对照组同步进入平台期，而呈持续缓慢上升趋势。结论：初步实现了体外猪前体脂肪细胞与肌卫星细胞的直接联合培养，并由研究结果显示其与对照组生长特性存在差异。     

光温生态因子对冬小麦幼穗分化的影响研究

对不同播期3个不同生态类型冬小麦品种幼穗分化进程系统观察研究结果表明,单棱期和二棱期为冬小麦对光温最敏感时期,其他幼穗分化发育时期对光温的反应与品种生态类型有关;试验播期范围内光温生态因子对冬小麦幼穗发育进程的影响作用以温度为主;气候变暖下通过调整播种期可调控冬小麦的幼穗发育进程。     

大豆黄酮对高邮鸭增重及血清某些激素水平和垂体GH mRNA表达的影响

基础日粮中添加3mg/kg大豆黄酮饲喂5日雄性高邮鸭（Anas platyrhynchos)，以观察大豆黄酮对其增重，血清T3，T4，IGF－1和垂体GHmRNA表达的影响。结果表明:前3周内实验组平均日增重提高16．29％（P＜0．01），饲料经提高7．26％，整个实验期的平均日增重提高7．20％，饲料利用率提高3．63％。同时，大豆黄酮显著增加血清T4（79．29％，P＜0．05）和IGF－1（36．78％，P＜0．01）水平，血清T3水平没有显著变化。Northern杂交分析表明，垂体GHmRNA水平提高32．12％（P＜0．01），提示大豆黄酮可以促进雄性高邮鸭的生长，提高饲料利用率，并能改变内分泌机能，影响垂体GH的基因表达。     

Quantitative expression analysis of GH3, a gene induced by plant growth regulator herbicides in soybean

Symptoms resembling off-target plant growth regulator (PGR) herbicide injury are frequently found in soybean fields, but the causal agent is often difficult to identify. The expression of GH3, an auxin-regulated soybean gene, was quantified from soybean leaves injured by PGR herbicides using real-time RT-PCR. Expression of GH3 was analyzed to ascertain its suitability for use in a diagnostic assay to determine whether PGR herbicides are the cause of injury. GH3 was highly induced by dicamba within 3 days after treatment (DAT) and remained high at 7 DAT, but induction was much lower at 17 DAT. GH3 was also highly induced at 7 DAT by dicamba + diflufenzopyr, and to a lesser extent by the other PGR herbicides clopyralid and 2,4-D. The non-PGR herbicides glyphosate, imazethapyr, and fomesafen did not significantly induce GH3 expression above a low constitutive level. These results indicate that a diagnostic assay for PGR herbicide injury based on overexpression of auxin-responsive genes is feasible, and that GH3 is a potential candidate from which a diagnostic assay could be developed. However, time course analysis of GH3 expression indicates the assay would be effective for a limited time after exposure to the herbicide.     

Effects of fertilization, crop year, variety, and provenance factors on mineral concentrations in onions

Mineral concentrations of onions (Allium cepa L.) grown under various conditions, including factors (fertilization, crop year, variety, and provenance), were investigated to clarify how much each factor contributes to the variation of their concentrations. This was because the mineral concentrations might be affected by various factors. The ultimate goal of this study was to develop a technique to determine the geographic origins of onions by mineral composition. Samples were onions grown under various conditions at 52 fields in 18 farms in Hokkaido, Japan. Twenty-six elements (Li, Na, Mg, Al, P, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Mo, Cd, Cs, Ba, La, Ce, Nd, Gd, W, and Tl) in these samples were determined by inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. Fertilization conditions and crop years of onions caused variations of P, Ni, Cu, Rb, Sr, Mo, Cs, and Tl concentrations in onions; different onion varieties also showed variations in numerous element concentrations. However, the variations of mineral compositions of onions by these factors were smaller than the differences between production places with a few exceptions. Furthermore, Na, Rb, and Cs in group IA of the periodic table, Ca, Sr, and Ba in group IIA, and Zn and Cd in group IIB showed similar concentration patterns by group; this result demonstrated that elements in the same periodic groups behaved similarly in terms of their absorption in onions.