Ascorbic acid (AA) is a powerful antioxidant and play as a cofactor for various enzymes in vivo. In this study, we investigated the effect of AA depletion on gene expression in the liver and lipid metabolism by using SMP30/GNL knockout (KO) mice which are unable to biosynthesis AA. First, we performed microarray analysis. Briefly, SMP30/GNL KO mice were weaned and divided into two groups; AA-depleted and supplemented groups, which mice were free access to water containing 1.5 g/L AA. After 4 weeks, mRNA was isolated and purified from the liver. In this study, Affymetrix GeneChip was used for microarray analysis. Actually, AA-depletion altered many gene expressions related to lipid metabolism. Especially, Cytochrome P450 7a1 (Cyp7a1), a late-limiting enzyme of bile acid biosynthesis, gene expression was significantly up-regulated. We also confirmed Cyp7a1 protein levels by Western blotting. Next, we investigated the influence of AA depletion on lipid metabolism. We examined the lipid and bile acid levels in the liver, plasma, and gallbladder from SMP30/GNL KO mice. Amount of total bile acid (TBA), free fatty acid (FA), total cholesterol (TC), triglyceride (TG), and phospholipids (PL) were measured by colorimetric method. AA depletion reduced TBA levels in the liver and gallbladder. However, FA, TC, TG, and PL in the plasma and liver were not changed by AA depletion. Although Cyp7a1 gene expression and protein levels were increased by AA depletion, amount of bile acid were reduced. Conclusively, we have shown that AA depletion reduced bile acid biosynthesis and elevated Cyp7a1 gene expression and protein levels. Thus, AA is an essential for bile acid biosynthesis pathway.
Ascorbic acid deficiency affects genes for oxidation-reduction and lipid metabolism in livers from SMP30/GNL knockout mice.
Sex, Specimen part
View SamplesGene expression of Ethanol-treated hepatocytes from WT and transglutaminase 2 knockout mice
Role of transglutaminase 2 in liver injury via cross-linking and silencing of transcription factor Sp1.
No sample metadata fields
View SamplesUnearthing of silenced genes in colorectal cancer (CRC) is of great importance. We employed oligonucleotide microarray to find changes in global gene expression of five CRC cell lines. These were analyzed before and after treatment with the 5-aza-2'-Deoxycitidine. Expression of the responding genes was integrated with gene expression profiling generated by microarray analysis of matched colorectal tissue samples. Selected candidates were subjected to methylation-specific PCR (MSP) and real-time quantitative reverse transcription-PCR using CRC cell lines and paired tumor and normal samples from CRC patients. Sixty eight genes were re-expressed after 5-aza-2'-Deoxycitidine treatment and over-expressed in normal colorectal mucosa, including genes that were known to be methylated in CRC. After applying study selection criteria, we identified 16 potential genes. Two candidates were selected (ASPP1 and SCARA5). Among 15 CRC cell lines, methylation was identified in SCARA5 (20%). The methylation status of SCARA5 was subsequently investigated in 23 paired colorectal tissue samples; methylation was detected in 17%, respectively. Observed promoter methylation showed a tendency towards methylation in tumor-derived samples, in SCARA5 gene. Significant down expression of SCARA5 mRNA was observed in CRC cell lines and tumor tissues compared to adjacent normal tissues (P < 0.001 and P = 0.001, respectively). The use of genome-wide screening led to the identification of a group of candidate genes. Among them, SCARA5 was methylated and markedly down-regulated in CRC. SCARA5 gene may have a role in CRC tumorigenesis.
Screening for epigenetically masked genes in colorectal cancer Using 5-Aza-2'-deoxycytidine, microarray and gene expression profile.
Specimen part
View SamplesGIST is considered to invariably arise through gain-of-function KIT or PDGFRA mutation of the interstitial cells of Cajal (ICC). However, the genetic basis of the malignant progression of GIST is poorly understood.
Distinct gene expression-defined classes of gastrointestinal stromal tumor.
Sex, Age
View SamplesThe purpose of the present study was to investigate the association of glutathione S-transferase P1 (GSTP1) expression with resistance to neoadjuvant paclitaxel followed by 5-fluorouracil/epirubicin/cyclophosphamide (P-FEC) in human breast cancers. The relationship of GSTP1 expression and GSTP1 promoter hypermethylation with intrinsic subtypes was also investigated. In this study, primary breast cancer patients (n = 123, stage II-III) treated with neoadjuvant P-FEC were analyzed. Tumor samples were obtained by vacuum-assisted core biopsy before P-FEC. GSTP1 expression was determined using immunohistochemistry, GSTP1 promoter methylation index (MI) using bisulfite methylation assay and intrinsic subtypes using DNA microarray. The pathological complete response (pCR) rate was significantly higher in GSTP1-negative tumors (80.0%) than GSTP1-positive tumors (30.6%) (P = 0.009) among estrogen receptor (ER)-negative tumors but not among ER-positive tumors (P = 0.267). Multivariate analysis showed that GSTP1 was the only predictive factor for pCR (P = 0.013) among ER-negative tumors. Luminal A, luminal B and HER2-enriched tumors showed a significantly lower GSTP1 positivity than basal-like tumors (P = 0.002, P < 0.001 and P = 0.009, respectively), while luminal A, luminal B and HER2-enriched tumors showed a higher GSTP1 MI than basal-like tumors (P = 0.076, P < 0.001 and P < 0.001, respectively). In conclusion, these results suggest the possibility that GSTP1 expression can predict pathological response to P-FEC in ER-negative tumors but not in ER-positive tumors. Additionally, GSTP1 promoter hypermethylation might be implicated more importantly in the pathogenesis of luminal A, luminal B and HER2-enriched tumors than basal-like tumors.
GSTP1 expression predicts poor pathological complete response to neoadjuvant chemotherapy in ER-negative breast cancer.
Age, Specimen part, Disease stage
View SamplesThis study explored the role of the growth hormone (GH) / insulin-like growth factor 1 (IGF-1) axis on the life-long caloric restriction (CR)-associated remodeling of white adipose tissue (WAT). Adipocyte size and gene expression profiles, using high-density oligonucleotide microarrays, were analyzed in WAT of six- to seven-month old wild Wistar rats fed ad libitum (AL) or subjected to a 30% caloric restriction (CR), and heterozygous transgenic dwarf rats bearing an anti-sense GH transgene fed ad libitum (Tg). While not significant in Tg rats, adipocyte size was significantly reduced in CR rats compared with AL rats. The microarray data based on the principal component analysis demonstrated that the gene expression profile of CR rats markedly differed from the AL rats, while Tg hardly differed, suggesting that CR-associated WAT remodeling was predominantly regulated in a GH/IGF-1-independent manner. The gene cluster with the largest change induced by CR included several genes involved in lipid biosynthesis and inflammation. Moreover, many of the genes transcriptionally regulated by sterol regulatory element binding proteins (SREBPs) were found in the cluster related to lipid biosynthesis. Real-time reverse transcription polymerase chain reaction analysis confirmed that the expression of SREBP-1 and its down-stream targets was particularly up-regulated in CR rats compared with SREBP-2 and its down-stream targets. Our findings suggest that SREBP-1 is a major transcription factor in CR-associated remodeling of WAT, and might be one of the key regulators of the anti-aging and pro-longevity effects of CR.
Caloric restriction-associated remodeling of rat white adipose tissue: effects on the growth hormone/insulin-like growth factor-1 axis, sterol regulatory element binding protein-1, and macrophage infiltration.
Age, Specimen part
View SamplesZinc-finger genes Fezf1 and Fezf2 encode transcriptional repressors. Fezf1 and Fezf2 are expressed in the early neural stem/progenitor cells and control neuronal differentiation in mouse dorsal telencephalon.
Zinc finger genes Fezf1 and Fezf2 control neuronal differentiation by repressing Hes5 expression in the forebrain.
Specimen part
View SamplesPaper abstract: The transcription factors Abrupt (Ab) and Knot (Kn) act as selectors of distinct dendritic arbor morphologies in two classes of Drosophila sensory neurons, termed class I and class IV, respectively. We performed binding-site mapping and transcriptional profiling of isolated these neurons. Their profiles were similarly enriched in cell-type-specific enhancers of genes implicated in neural development. We identified a total of 429 target genes, of which 56 were common to Ab and Kn; these targets included genes necessary to shape dendritic arbors in either or both of the two sensory subtypes. Furthermore, a common target gene, encoding the cell adhesion molecule Ten-m, was expressed more strongly in class I than IV, and this differential was critical to the class-selective directional control of dendritic branch sprouting or extension. Our analyses illustrate how differentiating neurons employ distinct and shared repertoires of gene expression to produce class-selective morphological traits.
Sensory-neuron subtype-specific transcriptional programs controlling dendrite morphogenesis: genome-wide analysis of Abrupt and Knot/Collier.
Specimen part
View SamplesOur previous investigation indicated that high-virulence C. gattii (C. gattii TIMM 4097) tend to reside in the alveoli, whereas low-virulence C. gattii (C. gattii TIMM 4903) tend to be washed out from the alveoli and move into the central side of the respiratory system. To test this hypothesis, we performed microarray assay.
How histopathology can contribute to an understanding of defense mechanisms against cryptococci.
Sex, Specimen part
View SamplesThere is a continuing need for driver strains to enable cell type-specific manipulation in the nervous system. Each cell type expresses a unique set of genes, and recapitulating expression of marker genes by BAC transgenesis or knock-in has generated useful transgenic mouse lines. However since genes are often expressed in many cell types, many of these lines have relatively broad expression patterns. We report an alternative transgenic approach capturing distal enhancers for more focused expression. We identified an enhancer trap probe often producing restricted reporter expression and developed efficient enhancer trap screening with the PiggyBac transposon. We established more than 200 lines and found many lines that label small subsets of neurons in brain substructures, including known and novel cell types. Images and other information about each line are available online (http://enhnacertrap.bio.brandeis.edu). Overall design: Examination of 6 cortical mouse neuronal cell types. 5 of which are in layer 6 in 3 different cortical regions.
A Mammalian enhancer trap resource for discovering and manipulating neuronal cell types.
Sex, Cell line, Subject
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