MicroRNA-24 regulates apoptosis of cardiomyocytes after myocardial infarction

AIM：To evaluate the expression of miR-24 in infarcted myocardial tissues and to investigate the function of miR-24 during cardiomyocyte apoptosis in vitro and in vivo. METHODS：The mouse model of myocardial infarcton (MI) was established. The expression of miR-24 in the sections of infarcted myocardial tissues was measured by qRT-PCR. The expression of miR-24 was modified by transfecting oligonucleotide mimic and inhibitor of miR-24 into cardiomyocytes, or injecting lentiviral vectors intramyocardially. The apoptosis of cardiomyocytes was detected by Caspase-Glo 3/7 Assay System. The heart functions were determined by echocardiography and the scar size in MI model was observed with Masson trichrome staining. The apoptosis of infarcted myocardial tissues was detected by TUNEL method. Microarray and bioinformatic analysis were also used to predict the targets of miR-24. RESULTS：The expression of miR-24 in the infarct and border areas was down-regulated after MI. Overexpression of miR-24 in cardiomyocytes reduced the apoptosis induced by hypoxia. miR-24 transfection resulted in reduction of the scar size, and improved left ventricular fractional shortening (LVFS) and left ventricular ejection fraction (LVEF) of the mice in treatment group after 2 weeks. Furthermore, miR-24 reduced cell apoptosis in the infarct region. BCL2L11, ANK3 and SGPL1 may be the targets of miR-24 during the process of anti-apoptosis. CONCLUSION：miR-24 is down-regulated in the infarcted myocardial tissues. In vitro, miR-24 reduces apoptosis of cardiomyocytes induced by hypoxia. In vivo, miR-24 attenuates cell apoptosis in the infarct and border areas of the heart 2 weeks after MI, and ultimately improves heart functions.     

一种基于模板DNA的PCR扩增难易预测方法

借助赋予四种碱基A,G,C,T四个三维空间中的点(0,0,1),(0,1,0),(-1,-1,0),(1,0,0),将一条DNA序列转化为一个二十四维向量。在此基础上利用Fisher线性判别法对人类基因组中189条基因片段进行PCR扩增难易预测,识别率达到了90%。     

紫花苜蓿MsBBX24基因的克隆及耐盐性分析

盐胁迫是影响植物生长发育的主要非生物胁迫因子之一，BBX家族转录因子在植物色素积累、光形态发生、种子生长发育以及逆境适应等方面具有重要的调节作用。为明确紫花苜蓿BBX基因的功能，本研究使用Primer Premier 5软件根据NCBI数据库MsBBX24基因的序列设计特异性引物，以紫花苜蓿的cDNA为模板克隆MsBBX24基因。利用生物信息学软件对基因序列和结构进行分析，并与其他植物的BBX24进行比对和进化树构建，分析它们之间的进化关系。采用实时荧光定量PCR(qRT-PCR)分析MsBBX24基因的表达模式。利用DNA的酶切与连接方法构建MsBBX24过表达载体，采用农杆菌介导法将其转入野生型拟南芥，通过除草剂Basta筛选，以半定量RT-PCR鉴定获得阳性转基因植株。通过对野生型和MsBBX24转基因拟南芥植株的表型观察和生理指标测定分析它们的耐盐性。研究结果表明，MsBBX24基因编码区序列长723 bp，编码240个氨基酸，分子量为30.58 kDa，等电点为7.74,MsBBX24与鹰嘴豆和蒺藜苜蓿的BBX24具有较高的同源性。qRT-PCR检测结果表明，MsBBX24基...     

高温条件下miRNA-24对奶牛乳腺上皮细胞增殖与凋亡的影响

【目的】MicroRNA(miRNA)是一类长度约21-23个核苷酸的非编码小RNA分子,本研究旨在分析高温条件下miRNA-24对乳腺上皮细胞生长、凋亡的作用及其初步机制。【方法】体外培养奶牛乳腺上皮细胞,高温(41℃)处理所培养的细胞;应用miRNA基因沉默技术,抑制高温处理过的乳腺上皮细胞中miRNA-24的表达;采用细胞计数法分析细胞增殖情况;Hoechst33342/PI荧光染色、流式细胞术检测miRNA-24对乳腺上皮细胞凋亡的作用,Western blot检测凋亡相关因子表达变化。【结果】抑制miRNA-24的表达,高温条件下的乳腺上皮细胞增殖能力显著增强(P0.05),凋亡细胞数显著减少(P0.05),促凋亡因子caspases-8和caspases-3表达量下调。【结论】内源性miRNA-24对乳腺组织发育具有重要的调控作用,抑制miRNA-24的表达可以缓解高温诱导下奶牛乳腺上皮细胞凋亡发生率、促进细胞的生长发育。     

向日葵叶抗氧化成分24-亚甲基环木菠萝烷醇的分离提取

通过对向日葵叶乙酸乙酯、0.5%稀盐酸混合液提取物的氯仿萃取部分的分离纯化,得到一个化合物。经MS鉴定其分子量为440,为24-亚甲基环木菠萝烷醇,且为首次从该植物中分离得到。用普鲁士蓝法以茶多酚为对照研究该化合物的抗氧化活性。结果表明,24-亚甲基环木菠萝烷醇具有抗氧化活性,但比同浓度茶多酚的抗氧化活性要弱。     

添加乳酸菌对不同生长期全株早籼饲料稻青贮品质的影响

本研究分别选用处于抽穗期、乳熟期、蜡熟期和黄熟期的全株湘早籼24饲料稻做为青贮原料,以研究不同生长期和添加乳酸菌对全株湘早籼24饲料稻青贮料感官指标、营养成分和乳酸菌含量的影响。试验采用2×4两因子试验设计,每个生长期分别设对照组和乳酸菌组,乳酸菌组添加0.01g/kg(以鲜重计)的乳酸菌制剂,共8个处理,每个处理3个区组,每个区组6个青贮罐,共144个青贮罐。试验结果表明:(1)随着水稻生长期的延长,水稻的DM、OM含量极显著增加(P0.01);CP含量在前三个生长期逐渐降低;前两个生长期的WSC含量和ADF含量极显著高于后两个生长期(P0.01)。(2)感官评定结果以第三个生长期最好,添加乳酸菌有改善青贮料色泽和气味的趋势。青贮料的pH值以抽穗期的最低,黄熟期的最高;随着生长期的延长,青贮料的DM含量极显著上升(P0.01),干物质回收率呈下降趋势(P0.05);氨态氮和氨态氮/总氮比值在前三个生长期呈上升的趋势。(3)添加乳酸菌明显提高了各生长期青贮料的pH值,极显著提高了各生长期青贮料的乳酸菌含量(P0.01),同时添加乳酸菌提高了青贮料中DM、OM含量(P0.05或P0.01)和干物质回收率(P0.01)。     

Chemical composition of the green alga Codium Divaricatum Holmes

A new sterol, 24-R-stigmasta-4,25-diene-3β,6β-diol (1), along with three known compounds (2–3), was isolated from the green alga Codium divaricatum Holmes, a traditional Chinese medicine, which is efficacious against cancer. All structures were determined by spectroscopic methods and comparison with related known compounds. Single-crystal X-ray crystallography allowed us to confirm the structure of 1. To our knowledge, the compound 1 is reported as the first from natural source, and compounds 2, 4 have not been isolated from green algae before.     

机插武运粳24高产形成规律与栽培技术研究

通过2009~2010年示范方资料分析,初步探明了超级稻品种武运粳24在机插条件下的生育规律和产量700 kg/667 m2的栽培技术指标。结果表明,武运粳24高产超高产是以足量的有效穗与较大的穗型,单位面积颖花量3000万以上,并保持正常的结实率和千粒重。配套栽培技术措施应围绕基质育秧、适期精量播种、插足基本苗、精确肥水运筹和综合防治病虫害等栽培手段,塑造超高产的库容量,实现稳定超高产。     

芥菜开花整合子SOC1与AGL24蛋白K结构域的互作位点鉴定

芥菜开花整合子SOC1与AGL24相互作用能够调节开花时间。为了深入研究SOC1与AGL24蛋白互作的分子机理,利用ISIS系统在线预测了SOC1/AGL24互作位点,并分别在MIKC型蛋白SOC1和AGL24的K域构建了5个SOC1突变体和3个AGL24突变体。酵母双杂交和β–半乳糖苷酶活性检测表明：突变体AGL24R137L和AGL24E169L能够与SOC1蛋白互作,但作用强度与SOC1/AGL24差异不显著;然而AGL24蛋白第107位的谷氨酰胺突变为亮氨酸后（AGL24Q107L）,则与SOC1的作用消失。说明SOC1/AGL24的作用强度能够被AGL24蛋白K域第107位调节,但可能不受第137和169位调控。进一步研究发现：SOC1V77K、SOC1P81K、SOC1K108V、SOC1R109L和SOC1C137K突变体均能与AGL24相互作用;但SOC1V77K、SOC1P81K、SOC1K108V和SOC1R109L突变体与AGL24的作用强度均显著低于SOC1/AGL24,而SOC1C137K突变体与AGL24的作用显著高于SOC1/AGL24。说明SOC1/AGL24的作用强度能够被SOC1蛋白K域第77、81、108、109位负调控或者第137位正调控。这为利用氨基酸位点调节SOC1/AGL24的深入研究及其开花时间分子调控奠定了基础。