Effects and mechanism of miRNA-24 on the proliferation,migration and tube formation of vascular endothelial cells

Objective:To investigate the effect and mechanism of miRNA-24 on the proliferation,migration and tube formation of vascular endothelial cells.Methods:Human umbilical vein endothelial cells(HUVECs)were assigned into control,microRNA(miR)-24 overexpression and anti-miR-24 groups.The proliferation and migration abilities of HUVECs were detected by methyl thiazolyl tetrazolium(MTT)assay and scratch wound healing assay,respectively.The ability of HUVECs to form tubular structures was evaluated by a tube formation assay.The mRNA and protein expressions of vascular endothelial growth factor(VEGF)and transcription factor Sp1 were determined by RT-PCR,immunocytochemistry and western blotting,respectively.Results:The miR-24 overexpression group exhibited decreased cell proliferation and migration,and expressions of VEGF and Sp1 compared with the control group(P <0.01).No tube-like network structure was formed in the miR-24 overexpression group.However,inhibition of miR-24 in HUVECs markedly increased cell proliferation and migration,enhanced tube formation and expressions of VEGF and Sp1(P<0.05 or P<0.01).Conclusion:MiR-24 suppressed the proliferation,migration and tube formation of HUVECs,and the mechanism might be related to the down-regulation of VEGF expression.Sp1 might participate in this regulation process.

Effects of miR-24 on the expression of vascular endothelial nitric oxide synthase and nitric oxide level in rats

Objective:To investigate the effects of miR-24 on the expression of vascular endothelial nitric oxide synthase(eNOS)and plasma nitric oxide(NO)level in rats.Methods:The miR-24 over-expression plasmid was constructed.Twenty healthy male Sprague-Dawley rats were randomly divided into two groups:miR-24 group and blank plasmid group.Rats were injected with plasmid DNA in saline via the tail vein.After eight weeks,the rat artery was removed and HE staining was used to observe the morphological changes.The protein expression and activity of eNOS were detected by immunohistochemistry and enzyme-linked immunosorbent assay(ELISA),respectively,and the NO level in plasma was determined by nitrate reduction assay.Results:Compared with the blank plasmid group,the expression and activity of eNOS as well as the NO production in the miR-24 group was significantly decreased(P <0.05 or P <0.01).No significant difference in the morphology of vascular tissue was noted between the two groups.Conclusion:Up-regulation of miR-24 inhibits the expression of eNOS and NO production in rat vascular tissue.It may provide a bio-target for the development of drugs to treat cardiovascular diseases such as hypertension.

From surface loading to precise confinement of polyoxometalates for electrochemical energy storage

Because of abundant redox activity,broad tunability,and specific atomic structure,polyoxometalates(POMs or POM)clusters have attracted burgeoning interests in electrochemical especially energy stor-age fields.Nevertheless,due to the high solubility and fully oxidized state,they often suffer from elec-trically insulation as well as chemical and electrochemical instability.Traditional noncovalent loading or covalent grafting of POMs on conductive substrates have been successfully performed to overcome this problem.However,severe shedding or agglomeration of POMs arising from weak interactions with substrates or excessive entrapment or weak destruction in conductive supports cause significantly re-duced availability and stability.To this end,precise confinement of POMs into conductive supports has been tried to improve their dispersibility and stability.Herein,recent progress of PoMs from surface loading to precise confinement in the electrochemistry energy storage field is reviewed.Firstly,we il-lustrate the typical non-confinement methods(viz.covalent and non-covalent)for supported POMs in energy storage applications.Secondly,different strategies for precise confinement of PoMs in organic and inorganic materials for related applications are also discussed.Finally,future research directions and opportunities for confined POMs,and derived ultrafine nanostructures are also proposed.This re-view seeks to point out future research directions of supported PoMs in the electrochemistry-related fields.

27nt-miRNA对间充质干细胞向血管平滑肌细胞分化的影响

为探讨27nt-miRNA对间充质干细胞向血管平滑肌细胞分化影响,构建27nt-miRNA过表达、反义序列Anti-27nt-miRNA以及阴性对照的表达质粒,慢病毒包装后分别转染人脐带间充质干细胞(hUCMSC),加入Ⅳ型胶原诱导hUCMSC定向分化为血管平滑肌细胞。四唑盐(MTT)比色法检测分化后细胞活力,免疫细胞化学染色法检测分化后细胞SM22α(兔抗平滑肌22α,smooth muscle 22α)的表达,Western印迹法和RT-PCR检测分化后细胞内的SMA (兔抗平滑肌肌动蛋白,smooth muscle actin) mRNA、SM 22α mRNA及其蛋白质表达情况。经检测,27nt-miRNA过表达分化组与阴性对照组相比,细胞活力下降20.48%(P<0.05),SMA mRNA、SM22α mRNA及其蛋白质表达量明显升高(P<0.05);而Anti-27nt-miRNA分化组细胞活力上升了18.07%(P<0.05),SMA mRNA、SM22α mRNA及其蛋白质表达量下降(P<0.05)。综上所述,27nt-miRNA能够促进间充质干细胞向血管平滑肌细胞分化,并且抑制分化后的细胞活力。

基因组编辑产品的安全管理

基因组编辑技术是指利用特异性核酸酶的定点剪切活性与细胞内源DNA损伤修复活性,在基因组水平上对目的核酸序列或单个核苷酸进行定点修饰的基因工程技术,该技术可以对生物体基因组进行精确敲除、插入、单碱基突变或置换等编辑。目前,基因组编辑技术具有精确性、高效性及易操作性,应用范围日益扩大。文中简要概述了3种主要的基因组编辑技术工具及基因组编辑类型,介绍了美国、欧盟等国家和地区对基因组编辑产品的监管体制。同时,基于我国对转基因产品的安全管理原则与体系,初步提出了基因组编辑产品的安全管理思路。根据中间材料或产品中是否含有外源编辑酶蛋白基因成分对基因组编辑产品进行分类管理,含有外源编辑酶的材料应按现有转基因安全管理办法进行管理;中间材料或产品中不含有Cas9等编辑酶的材料应根据被编辑位点的特征进行具体分类管理。

Co-fermentation of waste activated sludge with food waste for short-chain fatty acids production:effect of pH at ambient temperature

Effect of pH ranging from 4.0 to 11.0 on cofermentation of waste activated sludge(WAS)with food waste for short-chain fatty acids(SCFAs)production at ambient temperature was investigated in this study.Experimental results showed that the addition of food waste significantly improved the performance of WAS fermentation system,which resulted in the increases of SCFAs production and substrate reduction.The SCFAs production at pH 6.0,7.0,8.0,and 9.0 and fermentation time of 4 d was respectively 5022.7,6540.5,8236.6,and 7911.7 mg COD·L^(-1),whereas in the blank tests(no pH adjustment,pH 8.0(blank test 1),no food waste addition,pH 8.0(blank test 2),and no WAS addition(blank test 3))it was only 1006.9,971.1,and 1468.5 mg COD·L^(-1),respectively.The composition of SCFAs at pH from 6.0 to 9.0 was also different from other conditions and propionic acid was the most prevalent SCFA,which was followed by acetic and n-butyric acids,while acetic acid was the top product under other conditions.At pH 8.0 a higher volatile suspended solids(VSS)reduction of 16.6%for the mixture of WAS and food waste than the sole WAS indicated a synergistic effect existing in fermentation system with WAS and food waste.The influence of pH on the variations of nutrient content was also studied during anaerobic fermentation of the mixture of WAS and food waste at different pH conditions.The release of NH_(4)^(+)-N increased with fermentation time at all pH values investigated except 4.0,5.0 and in blank test one.The concentrations of soluble phosphorus at acidic pHs and in the blank test one were higher than those obtained at alkaline pHs.Ammonia and phosphorus need to be removed before the SCFAsenriched fermentation liquid from WAS and food waste was used as the carbon source.

Establishment of an efficient seed fluorescence reporter-assisted CRISPR/Cas9 gene editing in maize

Genome editing by clustered regularly interspaced short palindromic sequences(CRISPR)/CRISPRassociated protein 9(Cas9)has revolutionized functional gene analysis and genetic improvement.While reporter-assisted CRISPR/Cas systems can greatly facilitate the selection of genome-edited plants produced via stable transformation,this approach has not been well established in seed crops.Here,we established the seed fluorescence reporter(SFR)-assisted CRISPR/Cas9 systems in maize(Zea mays L.),using the red fluorescent Ds RED protein expressed in the endosperm(En-SFR/Cas9),embryos(Em-SFR/Cas9),or both tissues(Em/En-SFR/Cas9).All three SFRs showed distinct fluorescent patterns in the seed endosperm and embryo that allowed the selection of seeds carrying the transgene of having segregated the transgene out.We describe several case studies of the implementation of En-SFR/Cas9,Em-SFR/Cas9,and Em/En-SFR/Cas9 to identify plants not harboring the genomeediting cassette but carrying the desired mutations at target genes in single genes or in small-scale mutant libraries,and report on the successful generation of single-target mutants and/or mutant libraries with En-SFR/Cas9,Em-SFR/Cas9,and Em/En-SFR/Cas9.SFR-assisted genome editing may have particular value for application scenarios with a low transformation frequency and may be extended to other important monocot seed crops.

Agent-based dynamic simulation of an electricity market with multilateral bidding

The electricity market is a complex system in which participants interact and compete with each other,which makes description of them with mathematical models difficult.To solve these difficulties,computer simulation has become one of the main methods for studying electricity market problems.How to establish a reasonable electricity market has always been a major research issue in the electric power industry,for which a key point is the bidding mechanism.Agent-based modeling and a simulation(ABMS)method are used in this paper to study the imperfect competitive electricity market.An agent-based simulation method of multilateral bargaining game theory in the dynamics of the power bidding market is presented,and a multi-agent power market bidding dynamics simulation model based on game theory is established.The dynamic bidding game behavior among the government,power grid companies,power plant companies,and consumer parties is simulated in the market,and the simulation method is realized by Anylogic software.Finally,an agent-based four-party competitive dynamic game simulation in the electricity market is implemented,which provides a theoretical reference for further understanding resource optimization problems in the electricity market.

The enhanced electronic communication in ferrocenemethanol molecular cluster based on intermolecular hydrogen-bonding

This work presents an electrochemical study of enhanced electronic communication based on intermolecular hydrogen-bonding in ferrocenemethanol （described as FcCH2OH） molecular clusters. The enhanced electronic communication in FcCH2OH clusters is confirmed and further investigated by differential-pulse voltammetry and cyclic voltammetry. A key finding is that this enhanced electronic communication increases the standard rate constant of the electron transfer process. These results will provide us with a further understanding of the electronic communication within the ferrocenyl derivariv~ which it ha^pd nn rhp inr^rmnlpcldar hvdrn^en-hnndinct