hsa-miR-1908上游启动子区的生物信息学分析

目的利用各种生物信息学工具预测hsa-miR-1908上游启动子功能,以进一步研究其在人脂肪细胞中的转录调控机制。方法应用Ensemble数据库获取hsa-miR-1908上游启动子序列,利用多种在线相关软件预测出甲基化部位和转录因子结合部位。结果获取hsa-miR-1908上游启动子序列全长1 458 bp。miR-1908启动子序列中CpG岛位于(438~756)bp、(836~937)bp、(979~1374)bp处,CpG岛的存在会抑制miR-1908启动子的转录。miR-1908有15个转录因子的结合位点。结论 miRNA启动子相关生物信息学的研究,提高对启动子的研究效率,为进一步研究miR-1908的转录调控机制提供了重要的信息。     

肾素-血管紧张素系统基因多态性与原发性高血压的关系

原发性高血压是一种多基因病,受遗传以及外界多种因素的影响,本文介绍了影响原发性高血压基因中的肾素-血管紧张素系统基因,分别就肾素基因、血管紧张素原基因、血管紧张素转换酶基因、血管紧张素受体基因的研究进展作一综述.     

不同浓度葡萄糖和游离脂肪酸对大鼠骨骼肌细胞株L6细胞胰岛素敏感性和细胞内活性氧的影响

目的研究不同浓度的葡萄糖和游离脂肪酸（FFA）对骨骼肌L6细胞胰岛素敏感性及细胞内活性氧（ROS）的影响。方法L6细胞诱导分化成熟后,分为6组,以5mmol／L葡萄糖为低糖对照组,其中加0．3或1mmol／L的混合FFA为低糖低FFA或低糖高FFA组,以25mmol／L葡萄糖为高糖对照组,其中加0．3和1mmol／L的FFA的培养基为高糖低FFA或高糖高FFA组。干预48h,^3H—D葡萄糖摄取实验（加与不加100nmol／I,胰岛素37℃30rain）验证L6细胞胰岛素敏感性,经荧光探针H2DCFDA观察细胞内ROS含量的变化。结果在5mmol／L葡萄糖组,低糖对照组基础摄糖值为22777．6±6608．7,低糖低FFA组为26027．5±4085．7,低糖高FFA组为146805．1±21099．4。胰岛素刺激后,低糖对照组为76586．5±18450．1,低糖低FFA组为43738土9203．6,低糖高FFA组为32050．6±3362．3,较低糖对照组显著降低（P〈0．01）。在25mmol／L葡萄糖组,基础葡萄糖摄取量为11793．8±551．4,高糖低FFA组11887．3±2082．3高糖高FFA组为13886．1±3872．9,差别无统计学意义（P〉0．05）,但较低糖对照组显著降低（P〈0．01）．加入胰岛素刺激后,高糖对照组为42798．8±9441．5,高糖低FFA组为23946．9±3839．6,高糖高FFA组为13886．1±3872．9,各组之间差别显著（P〈0．01）。对细胞内R0s的研究发现,低糖低FFA组为2234．2±477．2,低糖高FFA组为1969．0±480．9,高糖对照组为1969．0土229．4,高糖低FFA组为2]84．5±734．2,高糖高FFA组为2571．3±96．7,可以显著增加的L6细胞内ROS,与低糖对照组（615．3±244．3）相比差别显著（P〈0．01）。除对照组之外的各组之间差别无统计学意义（P〉0．05）。结论高糖和高FFA可以诱导L6细胞出现氧化应激,同时高糖和高FFA是导致骨骼肌细胞胰岛素抵抗的重要原因之一。     

LYRM1基因过表达对3T3-L1脂肪细胞线粒体代谢的影响

目的观察LYRM1基因过表达对3T3-L1脂肪细胞线粒体代谢的影响。方法体外培养3T3-L1前体脂肪细胞,分别构建LYRM1基因过表达细胞株(LYRM1-pcDNA3.1/myc-His B)和空载对照细胞株(pcDNA3.1/myc-His B);实时定量RT-PCR验证转染情况;RT-PCR检测诱导分化成熟后的线粒体代谢酶HKI,ACC,CS,CPT1和Cyc-C基因表达水平。结果 RT-PCR结果证实LYRM1质粒转染成功;与空载对照组比较,LYRM1过表达组HKI,ACC,CS,CPT1和Cyc-C mRNA表达水平均显著降低(P均<0.05)。结论 LYRM1基因过表达下调了3T3-L1脂肪细胞中线粒体的代谢关键酶基因表达水平,可能参与调节脂肪细胞线粒体的代谢。     

hsa-miR-100的生物信息学分析

目的 对hsa-miR-100进行靶基因、功能预测等生物信息学分析,为深入研究hsa-miR-100功能提供理论和试验基础.方法 利用Pubmed检索miRNA-100相关文章,通过miRBase、NCBI、UCSC Browser等在线工具分析hsa-miR-100序列,应用miRanda、TargetScan及PicTar预测hsa-miR-100靶基因,结合已证实的靶基因进行功能富集分析和信号通路富集分析.结果 hsa-miR-100与多种肿瘤发生、发展有关,其序列在各物种间具有高度保守性.hsa-miR-100靶基因功能富集于基因沉默、染色质沉默、细胞生物合成负性调节等(P<0.01),涉及肿瘤信号通路、溶酶体信号通路、凋亡信号通路等信号转导通路(P<0.05).结论 hsa-miR-100可能参与肿瘤发生相关的生物学过程.     

PCB1254暴露致幼年斑马鱼视动反应异常及感光细胞发育相关基因表达变化

目的:研究受精后暴露PCB1254对斑马鱼幼鱼视动反应及视网膜感光细胞发育相关基因表达的影响。方法:对受精后斑马鱼胚胎进行不同质量浓度的PCB1254(0.125、0.25、0.5、1 mg·L-1)暴露处理,同时设立空白对照和0.01%甲醇对照组。暴露7 d后,观察幼年期斑马鱼视动反应及感光细胞发育相关基因CRX、RHO、SWS1、SWS2表达的变化。结果:(1)当条栅空间频率为0.20线·mm-1,移动速度为25 cm·s-1时,0.5 mg·L-1和1 mg·L-1组的幼鱼视动反应敏感比例明显降低(P<0.05)。(2)各实验浓度组的SWS2基因表达均明显下调(P<0.05),0.5 mg·L-1和1 mg·L-1组的CRX、RHO、SWS1基因表达均明显下调(P<0.05)。结论:0.5 mg·L-1和1 mg·L-1多氯联苯导致幼年期斑马鱼视动反应行为异常及感光细胞发育相关基因表达变化,提示须加强监测和控制环境毒物对儿童眼发育带来的不利影响。     

TrkB基因在脑源性神经营养因子治疗宫内缺氧缺血性脑损伤中的表达变化

目的:探讨酪氨酸激酶(TrkB)基因在尾静脉注射脑源性神经营养因子(BDNF)治疗官内缺血缺氧脑损伤中的表达变化.方法:钳夹孕鼠子宫动脉30 min后,尾静脉注射BDNF 1 μg或2 μg,持续5天,同时设立假手术组和生理盐水组为对照,RT-PCR和Western blot方法检测胎鼠TrkB mRNA和蛋白的表达变化.结果:孕鼠子宫动脉钳夹30 min后,可造成胎鼠TrkB的表达增高,并且进行尾静脉注射外源性BDNF可使TrkB表达增高更为明显.结论:通过尾静脉注射BDNF可明显上调胎鼠脑内TrkB的核酸和蛋白表达,加强BDNF对脑神经元的保护和修复作用.     

新生儿缺氧缺血性脑病外周血淋巴细胞中前列腺凋亡反应基因4 mRNA检测的临床意义

目的探讨测定新生儿缺氧缺血性脑病(HIE)外周血淋巴细胞中前列腺凋亡反应基因4(Par4)mRNA表达量的临床意义。方法HIE患儿37例为实验组(轻度14例,中度15例,重度8例),正常新生儿8例为对照组。两组在生后24h抽取外周静脉血1mL,采用Rt PCR法测定淋巴细胞中Par4mRNA表达量。结果轻、中、重度HIE患儿外周淋巴细胞中Par4mRNA表达量均较对照组显著上调(P均<0.01)。重度HIE患儿Par4mRNA表达量最高(F=64.6P<0.01)。结论测定外周血淋巴细胞中Par4mRNA表达量,对HIE的早期诊断和疾病严重程度的判断有一定临床价值。     

高脂饮食诱导下肥胖易感大鼠与肥胖抗性大鼠间部分生理学指标差异的研究

目的：探讨高脂饮食诱导下肥胖易感（OP）大鼠与肥胖抗性（OR）大鼠在体重、食量、Lee′s指数、脂肪湿重、血脂及脂肪组织蛋白脂酶（LPL）基因表达等方面的生理学差异。方法：48只大鼠，以高脂饲料饲养1周后，按体重增殖从大到小百分排序，取第75百分位以上 OP组，第25百分位以下为OR组，继续高脂饲养4周；观察各大鼠体重变化、摄食量、Lee′s指数、脂肪湿重、血脂等，采用Northern Blot分析脂肪组织中LPL基因的mRNA表达水平。结果：1.OP大鼠的体重增殖、热能摄入、Lee′s指数及腹腔脂肪湿重均显著高于OR大鼠，但血脂水平两组间无差异；2.高脂饲养1周、5周时OP大鼠体重增值分别是OP大鼠的6.54、4.25倍，热能摄入仅为OR大鼠的1.13、1.15倍；3.OP大鼠脂肪组织中LPL基因的mRNA表达水平显著高于OR大鼠。结论：OP与OR大鼠间存在生理学差异，其原因除OP大鼠热能摄入较多因素外，OP大鼠体内较高的能量效能是其肥胖易感性较高的重要因素，而能量效能与脂肪组织LPL基因的表达水平可能存在密切关系。     

孕早期胎儿颈项透明层在产前超声筛查胎儿畸形中价值的Meta分析

ObjectiveTo evaluate the value of nuchal translucency (NT) as a screening test for fetal abnormalities in the first trimester ultrasound examination.MethodsA search in Cochrane Library, PubMed, OVID, Springer, China National Knowledge Infrastructure (CNKI) and Chinese Bio-edicine Database（CBM）was performed to identify relevant English and Chinese articles between Jan 1990 and August 2008. Criteria for inclusion were established based on validity criteria for diagnostic research. Subsequently, the characteristics of the included articles were extracted. Statistical analysis was performed with Meta-iSc 1.4. Heterogeneity of the included articles was tested to select proper effect model to calculate pooled weighted sensitivity and specificity. Summary receiver operating characteristic curve(SROC) was made and the area under the curve (AUC) was calculated. Finally, sensitivity analysis was performed.ResultsTwelve articles were included, with a total of 112 099 fetuses. Nine articles meeting inclusion criteria were analyzed for the value of screening for cardiac abnormalities by nuchal translucency thickness above the 95th percentile for gestational age. The pooled sensitivity and specificity was 29.8%, 96.9%，respectively, AUC=0.804 7. Seven articles meeting inclusion criteria were analyzed for the value of screening for cardiac abnormalities by nuchal translucency thickness above the 99th percentile for gestational age. The pooled sensitivity and specificity was 18.9%, 99.3%，respectively, AUC=0.971 2. Five articles meeting inclusion criteria were analyzed for the value of screening for fetal abnormalities by nuchal translucency thickness above the 95th percentile for gestational age. The pooled sensitivity and specificity was 25.0%, 98.3% respectively, AUC=0.183 0. The sensitivity of screening for cardiac abnormalities by nuchal translucency thickness above the 95th percentile for gestational age was significantly higher than the nuchal translucency thickness above the 99th percentile for gestational age（χ2=6.58， P<0.05）,no difference was found in the specificity. The random?瞖ffect model was used in the analysis of screening for cardiac abnormalities by nuchal translucency thickness above the 95th or 99th percentile for gestational age because of the heterogeneity. The fixed-ffect model was used in the analysis of screening for fetal abnormalities by nuchal translucency thickness above the 95th percentile for gestational age because of the homogenicity. ConclusionsThe results suggest that screening for fetal abnormalities by NT thickness above the 95th percentile for gestational age has a low accuracy and is unsuitable for prenatal screen. At present it is incompletely clear on the sensitivity and specificity of screening for different kinds of fetal abnormalities by NT thickness. Screening for cardiac abnormalities by first trimester NT thickness has a high accuracy and specificity and can be reliably used in prenatal screen. We need the further systemic reviews to evaluate the value of NT as a screening test for different kinds of fetal abnormalities. Further multi?瞔entre and prospective studies are badly needed to be performed to optimize the standard of nuchal translucency thickness, evaluate the value of NT as a screening test for fetal abnormalities (especially cardiac abnormalities) in the first trimester ultrasound examination by a cost-effectiveness analysis, and develop an operation guideline on first trimester nuchal translucency thickness measurement for the prenatal screening of cardiac abnormalities in China.