Overexpression of microRNA-124 promotes the neuronal differentiation of bone marrow-derived mesenchymal stem cells

microRNAs(miRNAs) play an important regulatory role in the self-renewal and differentiation of stem cells. In this study, we examined the effects of miRNA-124(miR-124) overexpression in bone marrow-derived mesenchymal stem cells. In particular, we focused on the effect of overexpression on the differentiation of bone marrow-derived mesenchymal stem cells into neurons. First, we used GeneChip technology to analyze the expression of miRNAs in bone marrow-derived mesenchymal stem cells, neural stem cells and neurons. miR-124 expression was substantially reduced in bone marrow-derived mesenchymal stem cells compared with the other cell types. We constructed a lentiviral vector overexpressing miR-124 and transfected it into bone marrow-derived mesenchymal stem cells. Intracellular expression levels of the neuronal early markers β-III tubulin and microtubule-associated protein-2 were significantly increased, and apoptosis induced by oxygen and glucose deprivation was reduced in transfected cells. After miR-124-transfected bone marrow-derived mesenchymal stem cells were transplanted into the injured rat spinal cord, a large number of cells positive for the neuronal marker neurofilament-200 were observed in the transplanted region. The Basso-Beattie-Bresnahan locomotion scores showed that the motor function of the hind limb of rats with spinal cord injury was substantially improved. These results suggest that miR-124 plays an important role in the differentiation of bone marrow-derived mesenchymal stem cells into neurons. Our findings should facilitate the development of novel strategies for enhancing the therapeutic efficacy of bone marrow-derived mesenchymal stem cell transplantation for spinal cord injury.     

Common denominator genes that distinguish colorectal carcinoma from normal mucosa

Purpose Microarray technology has been used by a growing number of investigators and several studies have been published that list hundreds of genes differentially expressed by colorectal carcinoma (CRC) and normal mucosa (MC). On the basis of our own and other investigators microarray data, our goal was to identify a common denominator gene cluster distinguishing CRC from MC.Methods Thirty GeneChips (HG-U133A, Affymetrix) were hybridized, 20 with RNA of CRC stages I–IV (UICC) and 10 with MC. Expression signals showing at least a 4-fold difference between CRC and MC (p<0.01) were identified as differentially expressed. In addition, in our integrative data analysis approach only those genes whose expression was altered simultaneously in at least 2 of 5 recently published studies were subjected to an unsupervised hierarchical cluster analysis.Results We detected 168 up- and 283 down-regulated genes in CRC relative to MC. Twenty-three genes were filtered from the five articles reviewed. An unsupervised hierarchical cluster analysis of these 23 genes confirmed the high specificity of these genes to differentiate between CRC and MC in our microarray data.Conclusions Colorectal cancer and mucosa could be clearly separated by 23 genes selected for being differentially expressed more than once in a recent literature review. These genes represent a common denominator gene cluster that can be used to distinguish colorectal MC from CRC.     

二甲双胍对非酒精性脂肪性肝病大鼠肝脏基因表达谱的影响

目的 探讨二甲双胍对非酒精性脂肪性肝病(NAFLD)大鼠造模过程中肝脏基因表达谱的影响.方法 雄性Sprague-Dawley大鼠随机分为3组:对照组6只,模型组和治疗组各12只.治疗组在给予高脂饮食的同时,于实验开始第4周起按每天250 mg/kg加入二甲双胍干预.于实验第24周时处死,应用大鼠U230A芯片检测肝脏基因表达的改变.结果 与模型组相比,二甲双胍治疗组出现差异表达的基因共483条,其中上调基因133条,主要为激素受体基因、细胞周期相关基因及离子通道基因等,胰岛素受体及其底物、瘦素受体基因均有不同程度的表达上调,与模型组比较上升约3～7倍;下调基因350条,包括代谢酶相关基因、脂肪酸结合蛋白基因、细胞色素P450相关基因、炎症和凋亡相关基因,与纤维化相关的基因也略有下降.结论 从基因学角度分析显示二甲双胍可减轻肝脂肪变,改善肝脏炎症损伤和纤维化程度.     

利什曼原虫感染树突状细胞早期基因表达差异分析及关键基因筛选

目的:分析利什曼原虫感染树突状细胞(DCs)早期的基因表达与信号通路变化,探究DCs感染后应答,寻找利什曼原虫感染后基于DCs的免疫治疗方法。方法:GEO数据库下载利什曼原虫感染前后DCs基因芯片数据,RStudio软件筛选差异表达基因(DEGs),STRING构建DEGs蛋白质相互作用网络(PPI),Cytoscape筛选差异表达蛋白质的核心模块,RStudio软件对DEGs进行GO和KEGG富集分析。结果:共筛选出DEGs 129个,其中IL12B与CXCL10差异最为显著,GO分析共富集23个过程,主要涉及病毒感染过程相关细胞反应及Ⅰ-IFN相关免疫反应;KEGG分析共富集3条信号通路,分别为甲型流感、麻疹及DNA复制信号通路。结论:利什曼原虫感染DCs前后Ⅰ-IFN信号通路和TLR4/NF-κB信号通路激活,影响IL12表达,提示Ⅰ-IFN/IL12信号通路与TLR4/NF-κB/IL12信号通路可作为利什曼原虫感染治疗的靶点,CXCL10也有望成为潜在的治疗靶点;利什曼原虫感染后,出现类似病毒感染现象,推测抗病毒免疫疗法可能在对抗利什曼原虫感染中具有一定疗效。     

人脊柱裂胚胎脑干组织的全基因组表达谱

背景 神经管畸形的发病机理至今尚未阐明,较为公认的观点是由环境与遗传因素共同作用的结果。我们的研究旨在明确人脊柱裂胚胎的基因表达谱变化。方法 3例17周人脊柱裂胚胎经确诊后引产将其脑干组织提取总RNA,应用全基因组表达芯片Affymetrix HG-U133A 2.0 检测,对比正常对照组,将芯片结果数据做差异表达分析。 结果 差异表达基因为14500条,其中182条为显著差异,140条显著上调,42条显著下调。根据基因的生物学功能将其分类于19条通路,约50％的基因属于细胞凋亡,生长,粘附和细胞周期,应激,DNA复制和修复,信号传导,神经系统（NS）发育,氧化还原,免疫反应,基因转录调控通路。结论 人脊柱裂胚胎17周脑干的基因表达呈现出多生物学通路的差异改变。     

垂体特异性转录因子Pou1f1靶基因在不同证候H22荷瘤小鼠的表达特征

目的分析垂体重要功能基因及其垂体特异性转录因子(Pou1f1)靶基因在不同证候荷瘤小鼠的表达差异。方法将H22肝癌腹水细胞接种于190只昆明种小鼠腋下,并设置对照组,采用小鼠标准化四诊信息采集与辨证技术筛选典型的邪毒壅盛证、气虚证、阳气虚证、气阴阳虚证小鼠,并抽提小鼠垂体、下丘脑、肾上腺等组织RNA,采用基因芯片技术检测不同组织基因表达谱,本文重点分析不同证候垂体基因芯片数据。结果与对照组比较,垂体重要功能基因阿片促黑素皮质素原(Pomc)、生长激素(Gh)和催乳素(Prl)在早期的邪毒壅盛证和气虚证中表达下调约10%,而Pomc、Gh、Prl和促甲状腺激素β亚基(Tshb)在中晚期的阳气虚证和气阴阳虚证中表达上调30%以上。Pou1f1在垂体组织中表达最高,呈现组织特异性表达特征;垂体特异性转录因子Pou1f1和Neurod1仅在邪毒壅盛证上调,Tbx19和Egr1在不同证候中均呈现上调特征,Nr4a1、Nr4a2、Pitx1、Gata2、Nr4a3、Foxl2等基因在不同证候中均呈现下调特征。Pou1f1相关靶基因Crem、Tcf4、Rnf41、Lrpprc,Mrps18b、Eif3a、Lars,Arf4、Cep57、Vcpip1,Ptpn6、Myd88、F3,Lrrfip2、Dixdc1与Pou1f1基因表达模式类似,即在邪毒壅盛证上调。结论肿瘤状态下的不同证候小鼠,其垂体重要功能基因表达失常,垂体特异性转录因子Pou1f1及其靶基因在邪毒壅盛证具有类似的表达模式。     

A pilot genome-wide association study of early-onset breast cancer

High-density oligonucleotide microarrays containing a large number of single nucleotide polymorphisms (SNPs) have enabled genome-wide association (GWA) analysis to become a reality. We used the early access Affymetrix Mendel Nsp 250K chips in a GWA case–control pilot study to identify genomic regions associated with breast cancer. We included 30 randomly sampled incident invasive breast cancer cases aged <45 years without deleterious mutations in the BRCA1 or BRCA2 genes, and 30 population controls individually matched on age, ethnicity and geographical area. The overall genotype call rate was 97.13 ± 1.33% for controls and 97.48 ± 1.42% for cases. Comparison was made between cases and controls for 203,477 genotyped SNPs using (a) unconditional logistic regression (ULR), (b) conditional logistic regression (CLR) models with adjustment for the matched pairs, (c) allelic tests for single marker tests and (d) haplotype trend regression (HTR). Genomic control and EIGENSTRAT methods were used for correction of population stratification in appropriate models. We demonstrate the similarity and dissimilarity of results from different statistical analyses. We found several possible significant regions harboring biologically meaningful known candidate genes, such as genes encoding fibroblast growth factor, transforming growth factor, epidermal growth factor, and estrogen synthesis enzymes to be associated with early-onset breast cancer. In single marker analysis, none of the SNPs were statistically significant after correction for multiple testing. However, haplotype association tests, using 90730 tag-SNPs, suggested two regions in GLG1 and UGT1 genes retaining significance even after Bonferroni correction. Nevertheless, without systematic replication, findings from this pilot study, especially the associations of breast cancer in relation to specific SNPs, should be interpreted with great caution.