Effects of lovastatin on differentially expressed genes in HepG2 cells

AIM: To analyze the lovastatin-induced differential gene expression in HepG2 cells using a cDNA microarray assay. METHODS: Total RNA was extracted from the lovastatin-treated HepG2 cells and control group. cDNA was synthesized from RNA with Cy3/Cy5-labelled dCTP. Then the hybridization was conducted. The result was analyzed using Imagene and Genespring software. RT-PCR was carried to confirm the hybridization results. RESULTS: 30 genes were up-regulated while 11 genes were down-regulated in lovastatin-treated HepG2 cells, involved in some major functional areas including signal transduction, cell cycle regulation, tumor immunity, and so on. CONCLUSION: The analysis of differentially expressed genes in lovastatin-treated HepG2 cells is helpful to explore the mechanism of the anti-tumor activity of statins.     

石榴离体培养再生体系的研究

对石榴休眠枝段、成熟叶片及当年生新梢离体培养 ,建立其再生体系。结果表明 ,以休眠枝段、成熟叶片为外植体均能形成愈伤组织并分化出不定芽 ;当年生新梢茎段培养 ,以MS +BA 2 0mg·L-1+NAA0 3mg·L-1对茎段腋芽的增殖最适宜。诱导生根 ,用 1/2MS为基本培养基附加NAA 0 5mg·L-1+活性炭0 1mg·L-1+蔗糖 2 0g·L-1,生根率达 95 8%。培养基中附加 0 1%活性炭 ,对促进生根均有显著效果。     

Cortical gene expression pattern in rat focal cerebral ischemia

AIM: To investigate the genes differential expression in cortex during rat focal cerebral ischemia.METHODS: cDNA microarray chips containing numerous cDNAs were used to investigate the gene expression pattern between samples of focal cerebral ischemia and sham-control operation rats. RESULTS: Two hundred and eleven genes differentially expressed were screened out, among these genes, up-and down-regulated genes were 199 and 12, respectively. CONCLUSIONS: The analysis of gene expression pattern of focal cerebral ischemia based on cDNA microarray can realize high-throughput screening of the genes associated with the focal cerebral ischemia. The differential expression of genes may be related to the pathogenesis of focal cerebral ischemic diseases.     

Influence of ovariectomy and estrogen replacement on gene expression profile of myocardium in rats

AIM:To investigate the influence of ovariectomy and estrogen replacement treatment on profile of gene expression in myocardium by cDNA microarray,and to characterize the targeting genes of estrogen.METHODS:cDNA microarray containing 1 400 rat cDNAs was used to study the genes differentially expressed in myocardium between sham (Ⅰ),ovariectomy (Ⅱ,OVX) and estrogen replacement treatment (Ⅲ,OVX+E2) group.Then down-regulated genes in myocardium of OVX rats were further confirmed by RT-PCR.RESULTS:177 genes were differentially expressed in myocardium between sham and OVX rats,with 91 genes up-regulated and 86 genes down-regulated in OVX rats.164 genes were differentially expressed in myocardium between OVX and OVX+E2 rats,with 113 genes up-regulated and 54 genes down-regulated in OVX rats.There were 54 genes differentially expressed in OVX compared to sham and OVX+E2.They are involved in membrane channels and transporters (18),cell receptors (9),intracellular transducers/effectors/modulator (7) and metabolism (6).Most of the genes (45) were down-regulated in OVX rats and up-regulated in OVX+E2 rats.RT-PCR test confirmed the results of cDNA microarray.CONCLUSIONS:Long-term estrogen replacement may influence the expression of genes involved in membrane channels and transporters,cell receptors,intracellular transducers/effectors/ modulator and metabolism.Long-term estrogen replacement has some beneficial effects on ionic concentration and cardiac function which partially comes from the results of influence of expression on Na+,K+-ATPase and Na+/H+ exchanger.Estrogen has an inhibitory effect on the expression of dopamine receptor,which partially clarify the myocardial protection of estrogen.     

Differential expressions of ameloblastoma related genes determined by microarray

AIM: This study aims to screen the differentially expressed genes related to the pathogenesis of ameloblastoma by cDNA microarray. METHODS: The total RNAs were isolated from ameloblastoma and tooth germ, respectively. The RNAs were purified by oligotex. Both the mRNAs from two kinds of tissues were reversely transcribed to cDNA with the incorporation of fluorescent-labelled dUTP to prepare the hybridization probes. The mixed probes were hybridized to cDNA microarray. Tumor- related genes were screened through the analysis of fluroescent intensity. RESULTS: 722 genes exhibited significant changes in expression levels in the ameloblastoma in comparison with tooth germs tissues. 240 genes were overexpressed more than doubled (92 genes were more than 3-fold), and 482 genes were underexpressed to below 0.5 of the control level. CONCLUSION: Microarray technique facilitates large scale and rapid identification of potential target genes of ameloblastoma.     

荔枝采后果皮褐变过程中差异表达基因的SSH分析

 以‘妃子笑’荔枝果实为材料,采用抑制差减杂交（SSH）与cDNA 微阵列技术相结合,研 究了采后荔枝果皮褐变过程中的基因差异表达。分别以采后0 h 与32 h 的果皮总RNA 为驱动组与检测组, 构建了正向与反向SSH 文库,分别获得了282 个与76 个阳性克隆。通过cDNA 微阵列杂交筛选获得了在 采后32 h 果皮中上调表达克隆17 个,下调表达克隆49 个,分别代表了在采后32 h 果皮中上调表达基因 16 个和下调表达基因17 个,其中有较多的热击蛋白基因、糖代谢相关基因、细胞壁代谢相关基因等。 RT-PCR 检测基因表达结果与cDNA 微阵列杂交结果一致。     

利用c DNA-AFLP 技术研究苹果柱型与非柱型c DNA的差异表达

 以苹果(Malus×domestica Borkh. ) 柱型品种舞姿、非柱型品种富士及其杂交F₁群体中柱型、非柱型单株为研究试材, 应用cDNA-AFLP ( cDNA-amp lified fragment length polymorphism) 技术, 研究柱型与非柱型苹果cDNA的差异表达, 探讨了苹果柱型基因Co表达的分子机制。通过64对引物组合的cDNA-AFLP分析获得了1 630条在柱型与非柱型苹果中差异表达的片段。经过BSA ( bulked segregant analysis) 分析和反向Northern杂交鉴定, 获得了11个差异表达的cDNA片段, 并进行了克隆、测序和序列同源性检索分析。有5个片段在GenBank数据库中发现同源序列, 其余的6个功能未知。核酸和氨基酸比对分析中同源性最高的是片段A7和A16。A7的核苷酸序列同源于红叶石楠Photinia fraseri 26S核糖体RNA (97% ) 、蛋白同源于玉米的细胞色素P450单加氧酶(91% ) , A16的核苷酸(85% ) 及蛋白(93% ) 同源于直果草属Triphysaria versicolor的α-expansin 2基因。对A7、A16两个候选基因片段再进行正向Northern杂交验证,在富士中表达最强, 在非柱型后代、柱型后代及舞姿中表达依次减弱。由此推断, 由细胞色素P450单加氧酶基因所调控的赤霉素GAS变化影响了苹果柱型性状的表达。     

Construction of a genomic regulatory network based on gene expression profile of neonatal hypertrophic cardiomyocytes induced by phenylephrine

AIM: To construct a genomic regulatory network based on gene expression profiling of hypertrophic cardiomyocytes induced by phenylephrine in neonatal rats. METHODS: Cultured neonatal hypertrophic cardiomyocytes were induced by phenylephedrine. The gene expression profiles of these cells were assessed by using a cDNA microarray, and the microarray data were further analyzed by Pathwaystudio and Agilent Literature Search software. RESULTS: A genes/proteins interaction network was constructed with 450 nodes and 592 edges by analyzing the gene expression in hypertrophic cardiomyocytes and literature mining. The network belongs to scale-free network by topological analysis, and 14 genes/proteins as key nodes, including PTPN11, TRAF6, HSPA8, VIM, RPS6KA3, PTHRP, GRB2 and PI3K, were predicted. Based on GO analysis, the genes/proteins associated with metabolism, signal transduction and cytoskeleton may play important roles in the process of cardiomyocytes hypertrophy induced by phenylephedrine in neonatal rat. CONCLUSION: The genomic regulatory network based on gene expression profiling and literature mining may provide integrated clue to elaborate hypotheses about the evolution of cardiomyocyte hypertrophy.     

Screening differentially expressed genes involved in apoptosis of primary cultured rat cerebellar granule neurons by mRNA differential display RT-PCR

AIM: To Screen and identify differentially expressed genes that involved in apoptosis model in rat cerebellar granule neurons (CGNs).METHODS: The rat cerebellar granule neurons were isolated and primarily cultured.Fluorescent differential display RT-PCR (FDD RT-PCR) was performed to screen differentially expressed ESTs in the apoptosis model of primarily cultured rat CGNs.ESTs were subcloned into pGEM-T EasyTM vector and then sequenced.Alignment assay in non-redunant database was applied for encoding information.Reverse Northern blotting was used to appraise the results from DDRT-PCR.RESULTS: 164 pieces of differentially expressed ESTs were obtained by FDDRT-PCR.17 of them were subcloned and sequenced.5 ESTs of 17 were confirmed to be positive results by reverse Northern blotting.CONCLUSION: DD-PCR is a rapid,simple-operation and sensitive method for screening differentially expressed genes,which would contribute to the molecular mechanisms of apoptosis/survive of CGNs.     

PCR-select differential screening of a subtracted cDNA library of heat-adapted rat liver

AIM: To reveal the molecular mechanisms of heat adaptation by study the change of gene expression in rat liver when the rats exposed to hyperthermia stress and heat adaptation. METHODS: Differentially expressed genes in rat liver in association with heat adaptation were identified using the suppression subtractive hybridization (SSH) technique to prepare subtracted cDNA libraries in heat adaptation. The PCR-amplified cDNA fragments generated by SSH were then ligated into the plasmid pGEM-T (Promega). PCR-select differential screening technique was used to filtrate differentially expressed genes. Each of these differentially expressed genes was sequenced and was compared to known sequences in the GenBank database. RESULTS: eight up-regulating expressed genes segments were isolated from the up-regulating differentially expressed library, three of which were known gene such as p53 and five genes were new expressed sequence tags. CONCLUSION: Up-regulating expressed genes such as p53 maybe participate in the signal transduction pathway of heat adaptation.