阿尔茨海默病患者基因表达谱差异分析

目的 用基因芯片技术研究阿尔茨海默病(Alzheimer's disease,AD)患者与健康老人之间基因表达谱差异,筛选与AD病理过程相关联的基因。方法 分别抽AD患者和健康老人外周血白细胞的总RNA,逆转录合成cDNA,并分别以Cy5和Cy3荧光标记,作为探针,与2张含有4 096条双点人类全长基因的芯片进行杂交。扫描仪扫描芯片荧光信号图像,用软件对扫描图像进行数字化处理和分析。结果 AD患者与健康老人相比较,表达差异3倍以上共有30个基因。结论 AD患者与健康老人的基因表达存在差异,提示这些差异表达的基因可能与AD的发病及病理过程有关。

Genes Expression Profile Difference in Peripheral Blood Between Esophageal Carcinoma Patients and Normal Subjects

Objective： To study the genes expression profile differences in the peripheral blood between esophageal carcinoma patients and normal subjects using the gene chip technique and screen out the esophageal early conceration associated genes. Methods： The total RNA was extracted and purified in the peripheral blood obtained from the patients with esophageal carcinoma and normal subjects. The first strand of cDNA was synthesized through retro-transcription and labeled with Cy5 and Cy3 fluorescence as probes. The mixed probes were hybridized with a piece of 4096 double dot human whole gene chip. The acquired image was analyzed by microarrav suite software using a digital computer, and the intensity of ttuorescence signal and its ratio were calculated. Results： A total of 92 genes were screened out and its expression difference was more than 2 times in the peripheral blood between the patients with esophageal carcinoma and normal subjects. Among these, the expression difference of 36 genes was more than 3 times. Two human urokinase plasminogen activator surface receptor （UPAR） genes, 80K-L protein gene, human protein tyrosine-phosphatase gent arid proto-oncogene protein mRNA were significantly up-regulated, while the collagen V type （α-2 gene was markedly down-regulated. Conclusion： 80K-L protein gene, tyrosinephophatase gene, proto-oncogene protein arid the collagen V type α-2 gene might be associated with the ontogenesis, development and its metastasis in the esophageal carcinoma. The UPAR gene may play important roles in the diagnosing the micrometastasis in the peripheral blood of esophageal carcinoma.

Molecular Detection of Healthiness of Bombyx mori

[Objective] The paper was to explore the regularity between heat shock protein expression and the healthiness changes of Bombyx moil materials. [Method] The representative heat shock protein gene Bmhsp24.3 was screened by bioinfor- matic analysis method, and carried out real-time PCR expression analysis. [Result] The target gene Bmhsp24.3 expressed in different B. mori materials, but the expres- sion level in different materials significantly varied. The relative expression level of the gene had different degrees of changes under different rearing conditions. With the increase of rearing temperature, the gene expression was upregulated. The ma- terials with better healthiness had remarkable increase in expression of target gene, while the materials with poorer healthiness had less increase in expression of target gene. The expression difference of target gene Bmhsp24.3 was exactly consistent with the healthiness of breeds. [Conclusion] The healthiness of materials had rela- tionship with expression of target gene Bmhsp24.3. the higher the expression of tar- get gene Bmhsp24.3 was, the better the healthiness of materials was; conversely, the lower the expression of target gene Bmhsp24.3 was, the poorer the healthiness of materials was.

Wnt5a participates in hepatic stellate cell activation observed by gene expression profile and functional assays

AIM:To identify differentially expressed genes in quiescent and activated hepatic stellate cells(HSCs)and explore their functions.METHODS:HSCs were isolated from the normal Sprague Dawley rats by in suit perfusion of collagenase and pronase and density Nycodenz gradient centrifugation.Total RNA and mRNA of quiescent HSCs,and cultureactivated HSCs were extracted,quantified and reversely transcripted into cDNA.The global gene expression profile was analyzed by microarray with Affymetrix rat genechip.Differentially expressed genes were annotated with Gene Ontology(GO)and analyzed with Kyoto encyclopedia of genes and genomes(KEGG)pathway using the Database for Annotation,Visualization and Integrated Discovery.Microarray data were validated by quantitative real-time polymerase chain reaction(qRTPCR).The function of Wnt5a on human HSCs line LX-2 was assessed with lentivirus-mediated Wnt5a RNAi.The expression of Wnt5a in fibrotic liver of a carbon tetrachloride(CCl4)-induced fibrosis rat model was also analyzed with Western blotting.RESULTS:Of the 28 700 genes represented on this chip,2566 genes displayed at least a 2-fold increase or decrease in expression at a P<0.01 level with a false discovery rate.Of these,1396 genes were upregulated,while 1170 genes were downregulated in culture-activated HSCs.These differentially expressed transcripts were grouped into 545 GO based on biological process GO terms.The most enriched GO terms included response to wounding,wound healing,regulation of cell growth,vasculature development and actin cytoskeleton organization.KEGG pathway analysis revealed that Wnt5a signaling pathway participated in the activation of HSCs.Wnt5a was significantly increased in cultureactivated HSCs as compared with quiescent HSCs.qRTPCR validated the microarray data.Lentivirus-mediated suppression of Wnt5a expression in activated LX-2 resulted in significantly impaired proliferation,downregulated expressions of typeⅠcollagen and transforming growth factor-β1.Wnt5a was upregulated in the fibrotic liver of a CCl4-induced fibrosis rat model.CONCLUSION:Wnt5a is involved in the activation of HSCs,and it may serve as a novel therapeutic target in the treatment of liver fibrosis.

Role of H3K27 methylation in the regulation of IncRNA expression

Once thought to be transcriptional noise, large non-coding RNAs （IncRNAs） have recently been demonstrated to be functional molecules. The cell-type-specific expression patterns of lncRNAs suggest that their transcription may be regulated epigenetically. Using a custom-designed microarray, here we examine the expression profile of IncRNAs in embryonic stem （ES） cells, lineage-restricted neuronal progenitor cells, and terminally differentiated fibroblasts. In addition, we also analyze the relationship between their expression and their promoter H3K4 and H3K27 methyla- tion patterns. We find that numerous lncRNAs in these cell types undergo changes in the levels of expression and promoter H3K4me3 and H3K27me3. Interestingly, lncRNAs that are expressed at lower levels in ES cells exhibit higher levels of H3K27me3 at their promoters. Consistent with this result, knockdown of the H3K27me3 methyltransferase Ezh2 results in derepression of these IncRNAs in ES cells. Thus, our results establish a role for Ezh2-mediated H3K27 methylation in lncRNA silencing in ES cells and reveal that lncRNAs are subject to epigenetic regulation in a similar manner to that of the protein-coding genes.

Gene Expression Profiles in Porcine Tissues of Liver and Kidney

Microarray technologies are widely used all over the world for the gene expression analysis in various tissues, but still this technology has some limitations. The problem of eliminated reproducibility of the results, obtained in different laboratories using different platforms, is very relevant nowadays. For revelation of problems ofmicroarrays, the comparative analysis of hepatic and renal gene expression profiles （GEP） was carried out by using swine protein annotated oligonucleotide microarrays （SPAM）. Revealed differences in GEP between kidney and liver of pigs were correlated with functional and histological distinctions of these organs. It was shown that sources of errors in the comparative analysis of organ-specific GEP could be connected to the cross hybridization of one probe to transcripts （cDNA of mRNA） of different genes and to individual variability in gene expression between animals, related with the changeability of influences of exo- and endogenous regulation factors.

Correlation between the gene expression profiles of adenocarcinoma of esophagus and Barrett’s esophagus

Objective： The aim of this study was to investigate the characteristics of gene changes from Barrett＇s esophagus （BE） to esophageal adenocarcinoma by cDNA microarray. Methods： The cDNA retro-transcribed from equal quantity mRNA from esophageal carcinoma and BE tissues as well as control normal epithelium of esophagus which were from one patient with esophageal adenocarcinoma were labeled with Cy5 and Cy3 fluorescence as probes. The mixed probes were hybridized with two pieces gene chip respectively. It was scanned by laser scanner Scan Array 4000. The acquired images were analyzed by software GenePix Pro 3.0. Results： A total of 214 genes were screened out which expression levels were more than 2 times in hybridization of esophageal adenocarcinoma vs normal epithelium of esophagus, whereas 90 genes in hybridization of BE vs normal epithelium. A parallel comparison among these two gene profiles showed that a total of 45 genes with 24 downregulation and 21 up-regulation which expression levels were more than 2 times between the BE and the esophageal adenocarcinoma. Among these, there were 27 genes with 18 downregulafion and 9 up-regulation which implicated the tendencies progressing from BE to esophageal adenocarcinoma. Conclusion： These genes or their products which implicate the tendencies can be chosen as indicators of carcinogenesis with high risk index for BE.

Genome-wide analysis and expression profiling of the phospholipase D gene family in Gossypium arboreum

The plant phospholipase D （PLD） plays versatile functions in multiple aspects of plant growth, development, and stress re- sponses. However, until now, our knowledge concerning the PLD gene family members and their expression patterns in cotton has been limited. In this study, we performed for the first time the genome-wide analysis and expression profiling of PLD gene family in Gossypium arboretum, and finally, a total of 19 non-redundant PLD genes （GaPLDs） were identified. Based on the phylogenetic analysis, they were divided into six well-supported clades （tx, 13/？, 8, ~, ~ and q~）. Most of the GaPLD genes with- in the same clade showed the similar exon-intron organization and highly conserved motif structures. Additionally, the chro- mosomal distribution pattern revealed that GaPLD genes were unevenly distributed across 10 of the 13 cotton chromosomes. Segmental duplication is the major contributor to the expansion of GaPLD gene family and estimated to have occurred from 19.61 to 20.44 million years ago when a recent large-scale genome duplication occurred in cotton. Moreover, the expression profiling provides the functional divergence of GaPLD genes in cotton and provides some new light on the molecular mecha- nisms of GaPLDcd and GaPLD62 in fiber development.

Effect of electro-acupuncture on gene expression in heart of rats with stress-induced pre-hypertension based on gene chip technology

OBJECTIVE:To explore electro-acupuncture's(EA's)effect on gene expression in heart of rats with stress-induced pre-hypertension and try to reveal its biological mechanism based on gene chip technology.METHODS:Twenty-seven Wistar male rats were randomly divided into 3 groups.The stress-induced hypertensive rat model was prepared by electric foot-shocks combined with generated noise.Molding cycle lasted for 14 days and EA intervene was applied on rats in model + EA group during model preparation.Rat Gene 2.0 Sense Target Array technology was used for the determination of gene expression profiles and the screened key genes were verified by real-time quantitative polymerase chain reaction(RT-PCR) method.RESULTS:Compared with blank control group,390 genes were changed in model group;compared with model control group,330 genes were changed in model + EA group.Significance analysis of gene function showed that the differentially expressed genes are those involved in biological process,molecular function and cellular components.RT-PCR result of the screened key genes is consistent with that of gene chip test.CONCLUTION:EA could significantly lower blood pressure of stress-induced pre-hypertension rats and affect its gene expression profile in heart.Genes that related to the contraction of vascular smooth muscle may be involved in EA's anti-hypertensive mechanism.

De novo transcriptome assembly of RNA-Seq reads with different strategies

De novo transcriptome assembly is an important approach in RNA-Seq data analysis and it can help us to reconstruct the transcriptome and investigate gene expression profiles without reference genome sequences.We carried out transcriptome assemblies with two RNA-Seq datasets generated from human brain and cell line,respectively.We then determined an efficient way to yield an optimal overall assembly using three different strategies.We first assembled brain and cell line transcriptome using a single k-mer length.Next we tested a range of values of k-mer length and coverage cutoff in assembling.Lastly,we combined the assembled contigs from a range of k values to generate a final assembly.By comparing these assembly results,we found that using only one k-mer value for assembly is not enough to generate good assembly results,but combining the contigs from different k-mer values could yield longer contigs and greatly improve the overall assembly.