Inhibition of preadipocyte differentiation by Lycium barbarum polysaccharide treatment in 3T3-L1 cultures

BackgroundLycium barbarum (also called wolfberry), a famous Chinese traditional medicine and food ingredient, is well recognized for its significant role in preventing obesity; however, the molecular mechanisms underlying its preventive effects on fat accumulation are not well understood yet. The aim of this study was to determine the effects and mechanism of Lycium barbarum polysaccharides (LBP) on the proliferation and differentiation of 3T3-L1 preadipocytes. MTT was used to detect the proliferation of 3T3-Ll preadipocytes. Oil red O staining and colorimetric analysis were used to detect cytosolic lipid accumulation during 3T3-L1 preadipocyte differentiation. Real-time fluorescent quantitative PCR (qPCR) technology was used to detect peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), adipocyte fatty-acid-binding protein (aP2), fatty acid synthase (FAS), and lipoprotein lipase (LPL) expression.ResultsThe concentration of LBP from 25 to 200 μg/mL showed a tendency to inhibit the growth of preadipocytes at 24 h, and it inhibited the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner. In the preadipocytes treated with 200 μg/mL LBP, there were reduced lipid droplets in the cytoplasm, and its effect was opposite to that of rosiglitazone (ROS), which significantly reduced the PPARγ, C/EBPα, aP2, FAS, and LPL mRNA expression of adipocytes.ConclusionsLBP exerts inhibitive effects on the proliferation and differentiation of 3T3-L1 preadipocytes and decreases the cytoplasm accumulation of lipid droplets during induced differentiation of preadipocytes toward mature cells. Above phenomenon might link to lowered expression of PPARγ, C/EBPα, aP2, FAS, and LPL after LBP treatment. Thus, LBP could serve as a potential plant extract to treat human obesity or improve farm animal carcass quality via adjusting lipid metabolism.How to cite: Xu X, Chen W, Yu S, et al. Inhibition of preadipocyte differentiation by Lycium barbarum polysaccharide treatment in 3T3-L1 cultures. Electron J Biotechnol 2021;50. https://doi.org/10.1016/j.ejbt.2021.01.003     

IGF-II促MC3T3-E1细胞增殖和存活及影响NO水平的研究

目的　研究胰岛素样生长因子 2(IGF II)对小鼠成骨细胞株MC3T3 E1细胞促增殖、存活和影响一氧化氮(NO)水平的作用.方法　体外培养成骨细胞株MC3T3 E1细胞,分别加入不同浓度的IGF II,用MTT法、酶化学法检测MC3T3 E1细胞增殖和NO水平的变化.结果　IGF II对MC3T3 E1细胞有促增殖作用,在1～100ng/mL范围内呈浓度依赖性;第3天时100ng/mLIGF II组的NO水平明显低于对照组(P<0.01);培养5天和6天后,对照组细胞6天OD值明显低于5天OD值(P<0.01),而100ng/mLIGF II组细胞6天OD值则显著高于5天OD值(P<0.01).结论　IGF II能促进MC3T3 E1细胞的增殖,抑制细胞NO产生,并具有抗MC3T3 E1细胞死亡作用.     

IGF-Ⅱ促MC3T3-E1细胞增殖和存活及影响NO水平的研究

目的研究胰岛素样生长因子-2(IGF-II)对小鼠成骨细胞株MC3T3-E1细胞促增殖、存活和影响一氧化氮(NO)水平的作用.方法体外培养成骨细胞株MC3T3-E1细胞,分别加入不同浓度的IGF-II,用MTT法、酶化学法检测MC3T3-E1细胞增殖和NO水平的变化.结果 IGF-II对MC3T3-E1细胞有促增殖作用,在1～100 ng/mL范围内呈浓度依赖性;第3天时100 ng/mL IGF-II组的NO水平明显低于对照组(P<0.01);培养5天和6天后,对照组细胞6天OD值明显低于5天OD值(P<0.01),而100 ng/mL IGF-II组细胞6天OD值则显著高于5天OD值(P<0.01).结论 IGF-II能促进MC3T3-E1细胞的增殖,抑制细胞NO产生,并具有抗MC3T3-E1细胞死亡作用.     

Poly(dl-lactide)-degrading enzyme production by immobilized Actinomadura keratinilytica strain T16-1 in a 5-L fermenter under various fermentation processes

BackgroundPoly(dl-lactic acid), or PDLLA, is a biodegradable polymer that can be hydrolyzed by various types of enzymes. The protease produced by Actinomadura keratinilytica strain T16-1 was previously reported to have PDLLA depolymerase activity. However, few studies have reported on PDLLA-degrading enzyme production by bacteria. Therefore, the aims of this study were to determine a suitable immobilization material for PDLLA-degrading enzyme production and optimize PDLLA-degrading enzyme production by using immobilized A. keratinilytica strain T16-1 under various fermentation process conditions in a stirrer fermenter.ResultsAmong the tested immobilization materials, a scrub pad was the best immobilizer, giving an enzyme activity of 30.03 U/mL in a shake-flask scale. The maximum enzyme activity was obtained at aeration 0.25 vvm, agitation 170 rpm, 45°C, and 48 h of cultivation time. Under these conditions, a PDLLA-degrading enzyme production of 766.33 U/mL with 15.97 U/mL·h productivity was observed using batch fermentation in a 5-L stirrer fermenter. Increased enzyme activity and productivity were observed in repeated-batch (942.67 U/mL and 19.64 U/mL·h) and continuous fermentation (796.43 U/mL and 16.58 U/mL·h) at a dilution rate of 0.013/h. Scaled-up production of the enzyme in a 10-L stirrer bioreactor using the optimized conditions showed a maximum enzyme activity of 578.67 U/mL and a productivity of 12.06 U/mL·h.ConclusionsThis research successfully scaled-up the enzyme production to 5 and 10 L in a stirrer fermenter and is helpful for many applications of poly(lactic acid).     

Influence of Bcl-1 Gene Polymorphism of Glucocorticoid Receptor Gene (NR3C1, rs41423247) on Blood Pressure,Glucose in Northern Indians

Glucocorticoids and its receptor are known to be involved in the dysregulation of hormone and lipid levels. Therefore, we evaluated the association of Bcl1 gene polymorphism of glucocorticoids receptor (GCR) gene variant with hormone and lipid levels in Northern Indians obese. A total of 435 obese and non-obese age matched subjects were included in the case–control study. Lipid and hormonal levels were estimated using standard protocols. Analysis of +646 C>G NR3C1 gene polymorphism was done using PCR–RFLP. The frequencies of GR Bcl1, C>G genotypes and alleles did not differ significantly (P > 0.05) between obese and non-obese. The +646 G allele carriers had higher waist to hip ratio, blood pressure, insulin and glucose levels than non-carriers in obese subjects while diastolic blood pressure and glucose in non-obese. The NR3C1, +646 C>G polymorphism did not associate with obesity. However, the GG genotype may modulate blood pressure, blood glucose and hormonal levels in northern Indians.     

基于Logistic回归模型的区域生态用地演变影响因素分析——以京津冀地区为例

生态用地是人类赖以生存的基本资源与条件,保护生态用地,逐步恢复生态破坏严重地带,退还自然生态用地,对于维护生态平衡,改善区域生态状况,促进人与自然和谐,实现经济社会可持续发展,具有十分重要的意义。本文以京津冀地区为例,通过建立不同阶段各生态用地类型变化的logistic回归模型,很好地揭示了区域不同阶段土地覆被变化的驱动因素。主要结论如下：①对于林地变化,第一阶段（1980年一2000年）主要的解释变量是土壤表层有机质含量、坡度级I（〈5°）、到最近农村居民点的距离、到最近国道的距离和人均GDP,而在第二阶段（2000年-2005年）主要的解释变量是土壤表层有机质含量、坡度级I、地貌类型和农业人口占总人口的百分比;②对于草地变化,第一阶段（1980年-2000年）主要的驱动因素是土壤表层有机质含量,而在第二阶段（2000年-2005年）主要的驱动因素是到最近国道的距离;③对于湿地变化,第一阶段（1980年-2000年）主要的驱动因素是地貌类型,而在第二阶段主要的驱动因素是人均GDP。     

Rapid,one-step fabrication and loading of nanoscale 1,2-distearoyl-sn-glycero-3-phosphocholine liposomes in a simple,double flow-focusing microfluidic device

Liposomes are currently well-established as biocompatible delivery vehicles for numerous compounds. However, conventional manufacturing tends to rely on time-consuming processes, costly equipment, unstable reaction parameters, and numerous pre- and post-processing steps. Herein, we demonstrate a microscope-slide-sized alternative: a double flow-focusing microfluidic geometry capable of sub-hour synthesis and controlled loading of tunable liposomes. Using phospholipid 1,2-distearoyl-sn-glycero-3-phosphocholine as the bilayer constituent, the effect of varying the dissolved lipid concentration and flow rate ratio on synthesized liposome diameters was investigated and the encapsulation of fluorescent hydrophobic drug model ergost-5,7,9(11),22-tetraen-3β-ol was performed to ascertain the potential of this device as a loading platform.     

构建广州市科普基地认定和评估指标体系研究

通过对科普基地相关运营管理理论展开理论研究,对国内外科普基地管理的典型案例进行案例研究,总结科普基地运营管理的一般规律,在现行广州市科普基地认定、评估指标体系的基础上,对其进行设计、修改和完善。同时通过专家访谈并借鉴理论和实践经验,采用层次分析法对该指标体系进行权重赋值,构建广州市科普基地认定和评估指标体系,为提升广州科普基地运营管理能力提供有效依据。     

我国区域制造业数字化转型测度及影响机制研究

针对我国制造业数字化转型面临整体水平待提高、区域发展不均衡等问题,从效益提升、创新驱动和绿色发展3个维度构建区域制造业数字化转型评价指标体系,以熵值法作为衡量方法进行测度,并进一步从内部要素和外部环境两方面分析区域制造业数字化转型的影响因素。结果显示:我国制造业数字化转型水平整体呈现上升态势,但区域间发展极不平衡,总体处于"东高西低、梯度分布"格局;全国层面,人力资本和经济环境对制造业数字化转型的促进作用明显,资金投入和外贸环境则起负向作用;区域层面,因区位优势不同,各因素的影响作用也发生改变,其中人力资本对西部地区影响作用最大,制度环境对中部地区产生显著正向影响,而外贸环境对东部地区的影响作用被冲淡。最后根据研究结果,从优化产业布局、合理分配资金、平衡政策使用、加快经济发展、加大教育投资、优化外贸结构和加强基础设施建设7个方面提出推动我国制造业数字化转型的建议。     

面向科技工作者需求,强化科协组织人才工作 ——以安徽省科技工作者职业发展需求研究为例

围绕科技工作者需求,科协组织开展了一系列人才工作,着力增强科技工作者认同感、归属感、获得感,支持科技工作者成长成才,搭建学术交流合作平台,营造良好创新环境和助力科技工作者在经济社会发展中自我实现,为科技工作者的事业发展和价值实现提供了有力支持.面向新时代人才事业发展的新任务、新目标,本文以安徽省科技工作者为研究样本,进...     

甘蓝型双低油菜品种"华杂3号"在林芝地区的生态适应性研究

本文对甘蓝型油莱华杂3号在林芝地区的生态适应性进行了初步的研究，并以华杂3号在原产地武汉的经济性状为参照，分析其在本地区的适应性。结果表明，华杂3号在林芝的适宜播期为九月中下旬，迟于10月上旬，则不能越冬或减产；其每亩产量可达200公斤左右，比原产地增产25．28％，略低于常规品种Tower。研究表明，华杂3号油莱适应于本地区的生态条件，经济性状表现良好，产量高，可在林芝地区及生态类型相似的地方试种、推广。     

乡村振兴背景下基于扎根理论的农业科技人才胜任力模型构建研究

农业科技人才作为推进农业现代化的中坚力量,在乡村振兴战略实施中起到关键性作用。为厘清农业科技人才胜任特征内在构架,采用行为事件访谈法和扎根理论探索乡村振兴背景下农业科技人才必备胜任要素,充分构建新时代农业科技人才胜任力模型,包括专业知识、专业技能、身体素质、心理素质、道德品质、创新能力、风险管控和成就驱动等八大维度,以期为农业科技人才甄选、培训与开发及职业发展提供理论指导。